I think it's that kind of games that is hard to control using a keyboard, but there still a controller for the pc, so its kinda possible but not that much.
I don't see it happening...
I agree wholeheartedly with what latios_power has said.
On the other hand though, players could be advised to go out and purchase a USB Gaming Controller. Better yet it could come with the game.
It would be the only way to successfully put a SmackDown series game on the PC, without major problems.
If an off-line mode were to be added, I'd personally like to see a "proper" storyline laid out for the game, where ALL SUPERSTARS are given the chance to have their own custom storyline and all the SuperStars have their voices in the game.