I want it to be on the PS3 in some shape or form (exclusive or not).
From business standpoint, I wouldn't see the Wii as a great option for S-E for this game. Here's why:
1) Nintendo are notorious for not paying for exclusivity rights, they've been too used to it being given to them. Well, Sony and MS (particularly now after MS upped the ante) are willing .So I believe one of the 2 will get timed exclusivity
2) With the PS3 and 360 (assuming one gets timed exclusivity) you have a much better chance at reaching a much larger audience. I know you'll probably say that eventually the Wii may very well have more units out there than those two combined (it's edging closer to 50% each week). Problem is, how many of those Wii owners are regularly gaming. I for one know that I play with my Wii once every 2 months. You don't reach a larger audience if they aren't there to buy the games.
3) People often state that KH has never had crazy graphics and thus Wii would be a perfect fit for the art-style. Well, S-E uses CGI instead of constantly in-game engine for a reason, they want to wow people and draw them in with amazing art and graphics. Kingdom Hearts is no exception (imo).
4) Nomura loves the PS3, some say he's willing to leave S-E because of the lack of PS3 love. I'd assume he'd have a pretty big say in where the game goes, why wouldn't he choose for his own IP to go to the PS3 (and eventually the 360, I would assume, thanks to S-E's business sense).
I'm not saying I wouldn't buy the game if it came to the Wii, but aside from "Wii draws in kids and it's Disney!", I don't see much other reason why KH should/would come to the Wii (Please don't say because of keyblade waggle)