I think this time the Game shoudl focus a lot more in dividing the classes and the feels and the quests so that Eventually they may lead to complete different endings or Better .....
How about
Continue the quest further but as a second player ....
SO let's say you play the warrior and you complete the main quest then allow you to create a new character that is not a warrior and make other quests starting from the point where your warrior arrived ..... like if your warrior becomes king of the area then leave him as A NPC King and you get a new character to start with from the time events shaped from your previous character , that way the game will feel still new even if you replay it to complete other side quests or different class paths .... I would really like something like that ....
(PS Can a mod fix my mispelled topic title?)