I hate to sound a bit pessimistic but...are you really serious? Now that would be beyond awesome (and downright surprising). I think EB has a serious shot of making the AS team again if he returns to the 05-06 form, especially since Garnett is in the East now so there's one more PF spot open. I highly doubt CM will even get any considerations unless he puts up some solid numbers. Cassell...very unlikely, as he'll be fighting for a spot against Nash, D Williams, Parker, and Baron Davis. No chance.
I think Thornton is capable of being ROY but he's not the primary, secondary, or even third option on the time. The limited amount of PT (unless Mobley, Maggette, Thomas gets a serious injury) will prevent him from putting up serious numbers. My pick for ROY is Durant.