Crazy? Maybe. But let's look at the facts.
1. Nintendo's new controller is essentially a magic wand.
2. Many people on the internet have realized this and have talked at length about how cool it would be to have wizard duels.
3. Harry Potter is an immensely popular franchise. Nintendo loves money.
4. Current rights to Harry Potter are owned by EA.
5. Though EA has never been that interested in publishing for Nintendo,
according to this kind of boring but kind of interesting economic analysis of Nintendo's strategy, EA and Nintendo follow similar models and are in the same economic boat.
Nintendo has previously hinted that they may make a new mascot for the Revolution. This is not particularly strange; Nintendo released Pikmin as a new mascot for the Gamecube.
Given the controller, it would be insane for Nintendo to not create some sort of wizard game as a first-party release. This game, which would appeal to the same enormous demographic that reads Harry Potter, would inevitably resemble Harry Potter to a huge extent.
It is in EA's economic interest for the Revolution to succeed, and it would be in Nintendo's economic interest to make a Harry Potter wizard game, rather than a generic wizard game. The EA Harry Potter games for this generation of consoles have been pretty lackluster and are all basically ripoffs of Zelda anyway. EA could leverage its license while Nintendo actually develops the product and gets exclusivity and both parties would profit immensely.
I think it's possible. Of course, Miyamoto might want to create his own mascot, rather than steal Harry Potter. And EA might jump on the Revolution bandwagon by offering their own Harry Potter wizard game, which would suck, since the game wouldn't be as good as it would if Nintendo published it. EA could probably make more money selling the rights to Nintendo for this uge franchise, but they probably want to hold onto this valuable investment. Nevertheless, it would be cool.