why not just level up two new chars to 64(healer/tank)?

going to 10box seems a bit drastic, but thats just me =0. (I mean, to solve the content issue). I would probably just level a 2nd group, and then mix-n-match. as a bonus, you can always move the characters to separate accounts later.

I would think, just from what i've read/heard and from logic, wouldn't a serious 10-man team need 2-3 tanks and 2-3 healers? (Well, at least classes that can respec into those roles.) You might find the thread where nixi talks about kara helpful. I also always figured that if you did take 10-maning seriously, well, that it'd be kinda convenient to have each team function in 5-man content. Eg, have the ability to field two holy trinity groups, just so you don't have to take the one tank to instances twice when gearing up the 'other' group...but then again, im lazy, and really wouldn't know.