I think the class tuning is fine as it is in terms of numbers. As a raid leader in a CE guild, i think the issue is that not every class has utilities that are worth taking on every encounter. Rogue for example, has no utility to speak of unless you require frequent immunities to cheese mechanics, DK is pretty much the same unless you need his grip/limb. Same goes for Ret pala and so on. These are the classes that will see the bench whenever they're not numerically superior, because obviously you will never bench other classes that provide actual buffs (war, mages, enha, dh, priest, warlock and so on). What they should do, really, is make it so EVERY class brings a buff that is actually good, and make all buffs pretty much on the same level. That way, i will need to bring a DK just as much as i will need a warrior, and by eliminating this disparity if i have one spot to fill i will simply bring the best player. In my opinion this is the closest you can get to a balanced game.