According to the official Nintendo twitter, some of Pac-Man's abilities include "throwing fruit and eating power pellets." Pac-Man is also capable of turning into his classic pizza form for some of his moves.
His main design appears to be based off of his Pac-Man World 2 design, which was released on the Nintendo Gamecube among other systems. His other, pizza forms, are obviously based on his original design from the arcade days.
The Pac-Man ghost also find their way into the Pac-Man move-set, and they use their old 8-bit design. The ghost are also featured on the Pac-Man course, which is based on the Pac-Man arcade game.
Making his gaming debut in 1980, Pac-Man was joined in his reveal trailer by another creation from that year, veteran fighter Mr. Game and Watch.
It is no shock that Pac-Man made his way into the game, as Namco is working on the Smash Bros. 4 along with Nintendo. Most of the speculation however was about the design choice, and personally I think they made the perfect decision.
Now that Pac-Man is finally confirmed though you have to wonder one thing: How awesome is it going to be to have Mario, Sonic, Megaman, and Pac-Man all fight it out?