This is sweet if true.

http://news.teamxbox.com/xbox/16940/Rumor-Mega-Man-9-Coming-to-Xbox-Live-Arcade/

Capcom said it is wii ware only. Sorry. I do expect it to get ported to XBL, and PSN though after the wii release.

^yeah i think at first it will only be timed exclusive

The official word from Capcom is that it's a Wiiware exclusive. They didn't rule out the possibility that it would come to XBLA and PSN but for now it's still an exclusive.

Doesn't matter as long as it comes right?

Its possible, and most likely it will. I think they want to test the wii for a disc based megaman right now. Anyway I don't think it will stay exclusive unless sales are amazing.

I'm going to buy it for my Wii and therefore I will not buy it for my Xbox, even if it eventually makes it to XBLA.

I do not think Megaman 9 will be ported. I do not think that Capcom is willing to take the risk and the expense for such little return by putting the game on the PSN and XBLA.

Sorry, the game is bound to wiiware now:
http://arstechnica.com/journals/thumbs.ars/2008/06/27/megaman-9-to-be-the-first-game-to-hit-wiiware-xbla-and-psn

Well even though things have changed between Capcom and Nintendo it seems as though the classic megaman series will mostly remain on nintendos systems with 1 or 2 titles being ported as an exception.