Nintendo has a few cards up their sleeve, but they haven't been revealed yet.
According to Nintendo Benelux, Nintendo is currently working on 25 titles that have yet to be announced for the GameCube. The biggest news of all is that Nintendo is working on a "very special pokemon game" as well as a "special racer." Nothing is known about these titles at all. Some people have speculated that maybe the titles are playable over the internet.