After reading some of the stuff they're planning on doing with heroic scenarios, I might not object to an optional objective list based on role, per encounter, which increased your loot chances per objective met.
I mean, it'd be a lot more work for Blizz to put in, but imagine a Jin'rokh encounter in LFR which said:
Tanks:
Don't let the other tank gain more than X stacks of Static Wound (10%)
Have less than Y seconds of standing in conductive waters (5%)
Use a cooldown to mitigate Static Burstx10 (2%)
Use cooldowns to mitigate every Static Burstx10, minimum 5 (15%)
Heals:
Have MORE than Z seconds standing in conductive waters (5%)
If targeted by the ball lightning thing, do not let it hit you while standing in conductive waters (5%)
During a lightning storm, use 3 AoE healing spells. (5%)
During all lightning storms, use 5 AoE healing spells (15%)
etc, etc.
Obviously, the objectives could be tweaked to be fairly loose and able to be met with a modicum of effort. This would also discourage people queuing as healers and then DPSing because they'd lose a significant chunk of chance to get loot just for performing their role. And, in older raids, where the chance to get loot is already about 30%, you could possibly up it to about 50-60% with good performance (the %s up there are way theoretical, and probably too high, though there should be some "high reward" objectives). It can funnel players to good behavior on a fight and actually maybe somehow prepare them for normal modes.
Edit: And it would allow me to gear up my alts in old raids even quicker because this is stuff I already do!