I've been thinking about this kind of topic, and I want to discuss this a little further. In brief, while I am in favor of changing (or at least considering changing) many or even all of the surface elements of the game, I think that it is much more important that, when it comes to the deeper reasons why people play CoH -- the emotions that it triggers -- in that area we should preserve "as much as we can". The enemy groups, zones, storyline, and so forth - those can all change, and many of them should. But the nature of the game as a generic superhero MMORPG that's friendly to social and casual players and those who enjoy superpowered roleplay, and/or whatever else caused a lot of people to choose CoH ... we absolutely cannot afford to risk losing that in this particular project.
Mostly, I aimed this as an argument against copying entire chunks without much justification for doing so other than "City of Heroes had that." OK, so it did, but did it work? I think the most prominent issue from a conceptual standpoint is just how much like a comic book do we want the game to be? Having pretty much zero interest in American comic books of any fashion (never even watched most of the cartoons) didn't stop me from being a fan of City of Heroes for eight and a half years. And yet I'm seeing repeated insistence that we stick to comic book tropes and avoid using themes that don't show in comic books and DC this and Silver Age that and... Do we really want to be so adamant about making this a comic book before it is a game? I've said it many times that City of Heroes may have been a game inspired by comic books, but it was never a comic book simulator.
For instance, should we stick to the late 20th Century contemporary stable world setting? My first post here was a concept suggestion of a world in the 21st century, going out of my way to construct it so it would match modern urban living, just with larger structures, but with wilderness and monsters outside the city limits and that was bumped down to a possible alternate universe because we want a late 20th Century Silver Age world. Fair enough, I can work with what we all want to create, but should we really be afraid to change conceptual basics of the settings even if they let us retain nearly in full the thematic basics of the underlying world?
I'm advocating change not for the sake of being different or pretentious, but for the sake examining exactly what it is that we're trying to replicate. And yes, that does eventually lead to the big question - are we trying to replicate comic books, or are we trying to create an urban-setting super-powered MMO? Because those are not the same thing.
The question of rare drops sits at the intersection of the reward systems, powers balance, and crafting. The concept of rare drops injects scarcity into the balance and reward systems: certain activities generate scarcer rewards and those rewards are generally more valuable and more powerful. This can then be leveraged in ways that offer some meaningful benefit to the player over a longer period of time (sometimes but not always indefinitely).
What's the purpose of having rare drops? They serve several purposes. They break up the monotony of earning the same rewards over and over again while running content: having a range of rewards with different scarcity offers a generally more interesting reward experience, and rare and ultra rare rewards are simply the ones at the far end of the probability scale. They also generally gate certain content or ability statistically, so everyone isn't seeing exactly the same performance or content.
I'm not so much against "rare" drops as I am against RANDOM drops, to be honest. I have no problem with certain thresholds being difficult to achieve, but I do have a problem of repeating an activity like a Pavlov's dog, in the hope that maybe THIS time the random drop will give me what I want. I remember City of Heroes and random Shard drops. I remember running an entire four-hour play session and getting not a single Shard. I remember thinking I would have been better off not even firing up the game that day, because I would have gotten precisely the same amount of progress.
Make rare things rare by making them difficult to achieve, not by making them a crapshot to achieve. Say I want an Ionic Judgement, but I'm only level 40. I can't have that, obviously I can't. But at any point in time, I can look at my XP bar and go "Oh, wow, I have four more bars towards 41, around 10 more levels to 50. I'm making progress!" I can't say the same about random drops because running the content which generates the random drop and getting the wrong one puts me no closer to having it. It's a very fundamental rule of probability - previous rolls do not affect future rolls. Thus, a failed roll is my time, effort and enthusiasm flushed down the drain. It gives me no progress.
Gambling systems are corporate retention tools, anyway. With a straight up "bar-filling" system, player activity is highest towards the end of the bar, but drops off sharply once one bar is filled and the other starts as the player knows a reward won't be forthcoming too soon. This is scary for businesses because ZOMG! The player might stop playing and stop giving us money! Must trick him somehow! A "gambling" system produces a generally lower activity than peak bar-filling activity, but it does so at a constant rate. The player is always motivated to keep trying, even right after earning a big reward because... Well, every new try gives you the same chance. It's entirely possible you might get the next one right away.
Make things rare, just don't make them a crapshot to get.
Additionally, on the concept of packages: I dislike Inventions primarily because they force me to get a whole bunch of things I don't want to get the one thing I do want, and it usually comes in the "wrong" set. Defences from attack sets, damage from defence sets, better endurance from control powers, etc. It turns everything into a giant optimisation problem and resource-management, which stops being a game. Once you boil everything down decimal percentage points, you're basically pushing the player into number-crunching or dooming him to pretty random guesses as to what might work well. That's me in nearly every RPG I've played - I don't know what half the stats my gear gives me even do, and I can't tell a difference between having it and not having it.
Basically what I'm saying is you can have things to achieve without necessarily going the route of traditional loot. City of Heroes grew up without it, and I quite frankly liked the game more before I9. Back then, I spent a lot more time fighting stuff and a lot less time staring at MS Excel or the Market interface. I also recall a fair few people admitting to being "here" because there was no loot, no raids, etc.
Perhaps instead of letting new powers be gained by levelling alone, turn gaining access to them into missions or even brief story arcs as the character levels up. These could in turn be keyed to the character's Origin: a Natural character would have to train, a Magic character would have to track down an ancient spellbook, a Technology character would have to amass funds to purchase a new piece of gear, a Mutant would need to find a way to properly control the power and so on. There are many possible variations to play around with - even different ways to get at each, some of which could be locked (or unlocked) based on the character's prior history. Even the accessibility of the power while the character's efforts are in progress could be varied: a Natural would gain access to the skill as the training progresses, but need time to reach its' full strength, a Magician would gain it upon acquiring an instruction but find it acting unpredictably, and a Mutant would have little to no control over when it triggers and need to hold it in check somehow etc.
I'm not sure that's a good idea, because it runs into the same problem brought up every time someone suggests making origins "mean something:" What exactly do they mean? Right off the bat, you peg Magic characters as spellcasters, and that simply isn't the case. A fair few are demons, angels and other mystical creatures to whom magic is innate and thus they would be looking for power, not spells. Similarly, "train" is generic enough to apply to every character origin - it's why City of Heroes used it broad-spectrum. The worst thing you can do with origins is tie yourself down to a specific interpretation and thus limit player freedom and creativity. The beauty of City of Heroes was that Origins were kind of a suggestion, guiding you to the kind of concepts you may have wanted to use, but without locking you into one.
In the spirit of preserving the good about City of Heroes, this kind of freedom of interpretation is what bred the players' sense of ownership. You're not telling the players who their characters are, what they do and how they do it. You give them a world and let them decide this. I've hard this argument before, but to me, Plan Z needs to be a game which does not try to tie our characters to itself in any way, shape or form. Leave in the hooks there for us if we want to tie ourselves to it, but don't assume to know our characters. Treat them like guests in an alien world, to make themselves at home if they want to, or to claim they're just visiting if that's their thing.
Basically: Don't try to define who and what player characters are from the game's side. Let players handle that.