I consider all these PS2 to Wii ports an admission from 3rd parties that they should have released these games on the Cube in the first place. I mean, who do they expect is going to buy them now if they didn't the first time around?
Non-gamers? Yeah, right.
PS2 owners? They didn't care about it then, they wont care now.
Nintendo gamers? Bingo.
If you think about it this is happening because 3rd parties effed up twice: First when they ignored the Gamecube, and second because they didn't see fit to develop for Wii until it became popular so they need to fill the void with something.
I wont be buying Okami on Wii because I bought it shortly after it came out on PS2. I decided not to wait and see if it would get ported because it made too much sense. Also, Capcom had proven they were more than willing to port exclusives from Nintendo platforms, but not the other way around.
Personally, I found the game to be a little overrated. It's good, but it really doesn't do a whole lot that hasn't already been done in Zelda. And it IS a Zelda clone, though the combat is quite different, and the bosses are excellent and reasonably challenging.