Heroics are going to be tough. I have not leveled to that point yet so my first hand information is limited. However I do see 1 and 2 shotting of cloth classes in videos. That does not mean you cannot come up with creative ways to do them - kiting, etc. But it certainly will not be a cake walk.

5 boxing is tough as it is. I am still out on how viable my teams will be - I anticipate the warlocks will have much more success than the mages. But both could completely fail no matter what I do due to the class mix.

I tend to hope that is not the case but we will see. 5 cloths in heroics.. not the first choice and lets leave it at that for now.