Cloud looks like a very potent character based on the trailer, but we'll see once he's out in the wild. It looks like his special set is Cross-Slash (B)/Blade Beam (Side-B)/Climhazzard (Up-B)/Finishing Touch (Down-B) with Omnislash as his Final Smash.

I do have to hand it to Sakurai on this one; absolutely nobody I know saw this coming, and he managed to keep it under wraps until the official reveal.