I hope roles in the way they are implemented in 4E are dropped from the game. The combat roles in 4E were an artifact of the intense focus on tactical combat the game had. I prefer my game less combat based and my combat less tactical.
You can play ANY edition of D&D as combat-focused (or not) as you desire. 4E gave use tactical OPTIONS for combat. You don't need to use them but they're there if you want. You can stand there making melee basic attacks with your fighter if that's all you want to do.
Character's don't have to contribute equally to combat in a non-combat focused game; some characters (I'd say, Fighters) should be better in combat than everyone else. Everyone should be able to do something, but that something can be very small and doesn't need to be built into the mechanics (my level 1 wizard, carrying torches and reloading crossbows). Everyone needs a chance to shine, but not in combat, not necessarily.
Except it's a system that is made to cater to those who want a combat-heavy game (and everything in between) also. Your preferrence of game style is irrelevent to anyone but you. WotC needs to make a game that covers as many styles as possible.