A Job System for WoW
I like my main character in WoW. I have a ton of reputations maxxed out and a lot of achievements done. I do not want to have to re-accomplish all of that with a new character. Personally, I think it would be nice to have a "job change" system in WoW.
Now I am not talking about a permanent change of class, but instead a Final Fantasy-esque multi-classing of sorts. I would love if once you reached level 80 (or 85 for Cataclysm), you could pay for a "class slot". You would pick which class and be able to switch to a level 1 version of that class. The switch might have a one hour cool down, but does not necessarily need a cool down at all. It would work somewhat like the multi-spec in that when you switch you would start with no mana or energy.
Anyway, with that level 1 character all the quests in the game would be available for accomplishment even if you had accomplished them before. The only difference would be that if you had previously accomplished them on your main class, you would no longer gain reputation from the quest if the quest granted any. These re-opened quests could only be accepted, accomplished and turned in on your "leveling class". I could not create a mage secondary, accept a bunch of quests, switch to my paladin, complete the quests, and then switch back to my mage to turn them in.
Once you leveled your "leveling class" to max level, you could buy another slot. There would be no limit to how many of the classes you could level to max on one character. In essence, you could have on character that at will could switch to any of the classes at max level. The only restriction would be that you could only have one class in the leveling process at a time. You could not just get your character to max level and then buy nine class slots on the character at once.
This would probably take a great deal of work to implement, but I think it would be a great boon for the game. I know a great deal of people who have leveled multiple alts to max level but hate having to regrind all the reputations on those character and I agree that you should not have to. Another benefit would be for finding instance groups. A lot of times, I would want to run an instance on one character because I needed loot for that character, but with this system I could say "Okay, I will switch to my paladin and heal this instance, but if this piece of loot drops, I want a chance to roll on it for my mage."
Sure it might cause some loot bickering, but I think the benefits far out-way the negatives.