definitely wii bound, it just makes the most sense in so many ways:

1. Its already been relaesed on the wii
2. Japanese release soon(capcom has done that before... MHG anyone?)
3. Development costs on PS3 will be way higher, and they cant risk it can they?

God i hope its a sequel or prequel or whatever. As other posters have pointed out, the first one sold really bad and its not such a high profile game like street fighter or resident evil. So i can't see them making it for the ps3/xbox360 as it will cost more and they'll probably lose a crap load of money.

Also the first one is on the Wii pretty stupid to switch platform so the new players wont be able to play the first one, but still it has happened before. If it is for the Wii i can see it being ported to PS2 similar to other games like the upcoming Silent Hill Shattered Memories and TMNT: Smash Up

I'd almost bet money that  Okamiden is just going to be the name of the japanese release.

Like Resident Evil 5, Street Fighter 4, or Devil May Cry 4. Id love it to come to Wii, if its purely from the good graces of Capcom it wont happen.