Every MMO has a bar that you fill as you progress. For most games, this is limited to experience points and leveling. But I think Guild Wars 2 might be on to something with a few of the other “bars” it's introduced recently and could be one of the more innovative and forward-thinking mechanics the game has to offer.
A lot of elements of MMOs have become abstracted over the years, shifting the balance from “realism” to “convenience.” Most games insta-teleport you to a dungeon entrance these days, when you used to have to trudge to the door yourself. Loot collection has also become streamlined. Remember when you had to walk over to and double-click on a dead mob, see a screen with loot pop up, click on every one of them... seems like ancient times, doesn't it?
Convenient as it is these days, you can still miss loot if something dies far enough away from you or you die before it goes down (something GW2 has already “fixed” in WvW). Also, is there any real strategy involved in remembering to press V every time something dies? Or is it just something you do because the game tells you to, the purest “press button, get reward” implementation of the Skinner box?
Still, the pseudo-realistic notion of “drops” persists, that you get loot by killing a monster that supposedly had it on its body – never mind where the boar was keeping that greatsword, it just had it, OK?
The PvP reward tracks in Guild Wars 2 changed all that, introducing a means of obtaining loot that wasn't tied to individual drops. Instead, you'd effectively gain treasure based on how well you played, receiving loot at various points in your progress bar. That seems to have gone down really well, and now that ArenaNet has implemented a more robust “bar” mechanic in the Mastery system, why couldn't this be adapted to the whole game?
All right, the major reason it couldn't is because the game's not currently set up for that, and I imagine that replacing the non-PvP loot system would be a huge programming hassle. But if this works for GW2, maybe GW3 or other MMOs in the future, could adopt it. In fact, one already has.
Remember Black Gold Online? If not, I don't blame you. BGO was that game with that incredibly wonky loot system where you achieved a score during an hour of play and then got a loot bundle related to your score? What I'm suggesting – and what GW2 already does with its PvP and Mastery rewards – is actually not that different.
Where BGO got into trouble was with the fact that you only got two free loot bundles per day. (Well, along with the confusing UI, bad localization, boring combat...) If you played more than that, you'd have to pay cash to receive your loot. This wouldn't be an issue in any MMO that's run by actual sane people. Also, the “hourly” system was a pain to deal with. If you wanted to play for, say 45 minutes, you'd feel short-changed by “missing out” on another 15 minutes' worth of scoring; a permanent track that you can progress along, makes more sense.
Another question would be whether this would be too much abstraction. Illogical as it sounds, we expect to loot a greatsword from a boar, not receive a package of loot from out of nowhere at some regular interval. Still, nobody really blinks an eye at “bouncy” chests in Guild Wars 2, and we receive loot from NPCs in the mail all the time. Maybe instead of receiving loot directly from the mobs themselves, we could get mail at regular intervals saying “Good job!” and handing us our loot. That would help a little bit with the abstraction aspect of things.
It also seems easier to me to manage individual tracks, which I can only advance on one at a time, than it is to have to deal with a bunch of different tokens and currencies. A little freedom would be lost if something like this were implemented for dungeons, since you would have to progress along the pre-determined path for loot rather than spending your tokens however you wanted. It would help slow things down a little, though, and prevent players from getting all the best gear in a matter of days (or hours), but would reward them for their progress as they went. That seems reasonable to me, but it's another reason why it couldn't replace what we currently have.
There's a reasonable question to ask: Is this kind of system actually better than what we have now, or would the unfamiliarity with it – after all, we're all used to looting boars – not be worth the hassle? When I (briefly) played Black Gold Online, it was just weird not looting mobs, but I think with a little better explanation and time spent, it could seem natural. Any MMO mechanic seems second nature after you've done it long enough.
As for its advantages, not feeling the need to open your inventory every 30 seconds to check out/salvage what you've got would help streamline. Sometimes I do that, sometimes I wait until I'm at a stopping point, but the obsessive-compulsive gremlin inside of me always wants me to organize my loot now.
This could also reduce randomness. Imagine if every X minutes playing in Cursed Shore, you got a chest with a few T6 crafting materials, or if spending a lot of time in Dry Top could net you a guaranteed Unidentified Fossilized Insect. You could still work in some rare random rewards, like ascended chests, but anything that lets you “work toward” a reward rather than wait for it to come up as a random drop would be nice. This is the approach ArenaNet is coming up with for precursors, and it's what the game already did with PvP rewards.
MMOs are always trying to reduce or eliminate confusing decisions in games, and I think a progress-bar-based system, offering a kind of “fire and forget” means of loot acquisition, could help simplify an oft-confusing part of MMOs that's usually overlooked. Guild Wars 2 is already leaning in that direction, with the PvP reward tracks and the Mastery system and I'm in favor of ArenaNet expanding the concept in the future.