So I've seen tons of discussions on dungeon runs and pvp, but what about raids? What are peoples thoughts or experiences they have had with trying to box on raids?

What group comps and roles seem like you could bring the most benefit to the raid while being able to play your role at the maximum efficiency? It feels like tanking would most definitely be out and healing seems like it would be pretty difficult since it seems like it would be hard to focus on healing more than one target at a time where multiple non-boxed healers could be split up between different groups.

Maybe that just leaves something like trying to dps with a group of warriors, mages or locks on a raid?