Yep, it's one of the big hurdles they're either facing right now, or will be facing soon. Making it so that your talent choices matters somewhat less as to what your class can do (example, Shield of Righteousness is available to all Paladin specs and comes with a huge bonus threat modifier, which allows both Holy and Ret to produce acceptable TPS, and thus tank) makes classes with more than one role to fill - and that's almost all of them, folks - much more fun to play.
But single-role classes, like Rogues, Hunters, Mages, and Warlocks, are going to start feeling left out. Sure, how you spec changes how you do your DPS (well, kinda), but it doesn't change that you're always gonna be DPS.
Specifically to Rogues, I do think a number of problems they'll be facing is their strength in PvP. You really can't give them too many new tricks or abilities, because they're already extremely powerful in PvP - giving them more tricks would certainly make them overpowered, and they're pretty damn close to that point already (Deadly Brew, anyone?) You could make Sap usable on targets that're in combat, which would make Rogues more desirable for instances (as compared to a Ret pally which can do good DPS, toss some heals, buff the group, and do what amounts to an in-combat Sap), but would make them ludicrously powerful in PvP.
Personally, I think the best solution would be to completely and totally separate the PvP and PvE sides of the game, but that's a mammoth undertaking, and I'm not sure if we'll ever see it; and even if we do, it's probably gonna be a year or two from now, not a few months.