According to Joystiq, a WiiWare version of Excitebike is coming on November 9. It appears as though the revelation was made via the new weekly Nintendo Week program on the Wii that the game dubbed Excitebike World Rally will be a 2.5 version of the original game.
The track editor will also return and the game will even include online multiplayer.
Awesome, I always enjoyed Excitebike. I still think Excitebike 64 is the one of the best Motocross games ever made and I would like a sequel to that sooner or later.