All melee is gonna be a bitch. Valiona and theralion - which is the 2nd boss in whats 'considered' the entry raid in cata - requires you to move a lot, spread out, stack ... with a rather short enrange timer. The impossible can be done, boxers showed that in the past, but that were only a handful. But you said you have *just raided icc*. What does that mean? As in boxed icc or as in solo'd it with weekly pug and did 4-5 bosses? Or did you beat hard modes? Etc ... No disrespect, but raiding in cata works slightly different than raiding icc.

The best advice i can give you is to spend an hour or 2 watching cata raid videos on ytube. That will give you a good idea if it's possible or not. Better do that than level up 10 toons and realize you are screwed.