First Appearance: Mega Man
The Blue Bomber is an obvious choice, but there's a small chance he won't make the Smash Bros. roster due to copyrights. Chances are, though, is that we'll be seeing him in the next Smash Bros. game.
I could list literally hundreds of possible moves that Mega Man could have, but instead I'll just post a handful of pictures of his moves.
If Mega Man doesn't appear in Smash Bros., Sakurai better be ready to deal with a few million angry fans rioting. But I don't see this as a problem, considering the owner of the Mega Man franchise said he'd have no problem allowing Mega Man be in Smash Bros. Also, Mega Man has been appearing in a few Nintendo-exclusive games lately and kissing the big N's butt. Capcom knows how to play the game (no pun intended) and knows the importance of the publicity a character gets when they appear in Smash Bros. Just look at Mr. Game and Watch, Kid Icarus, and the Fire Emblem series.