I'd like to only have a pally MT and not worry about having an extra melee I don't need during the single tanking bosses or a healer that can't AoE as well as a mage/druid, but it would be really nice to have that extra buff!

Who knows, this is all theorycrafting for me anyway. I may move into 10 man if I can prove to myself I can be very successful with 5boxing, and that won't hapeen until expansion anyway.