I'll just say, if you have an HDTV and want to do online co-op with PSN friends (I believe there is online co-op, not sure), get it on PS3. If you are playing on an SDTV, then probably get it for Wii.
i have to go with Mana on this one but not to sure bout the online co-op i know there is local i dont even use my wii but think about cost how much you willing to spend on it. The prices will be different also
[quote name='PVJAG']I've got a nice HD set-up so I'm leaning towards PS3. And they actually cost the same (both $49.99). What about gameplay?[/QUOTE]If you LIKE motion controls (I hear it's optional on the Wii version), then get it. If you are perfectly happy with the gameplay on PS3 (there's a demo up), then just go ahead with it IMO.