I'd wait to see what more information is revealed about the Wii version.
Make sure it's not gonna be gimped somehou (and I mean by areas, items, plotlines, and such)
As far as the controls go, yu may want to rent RE4:Wii and see how you like it. For me the biggest problem with RE4 is the inability to reset the damn keys so I can't use the gun shell the way that would make sense to me (Nunchuck trigger for fire). To me that would be an essential problem to correct on RE5 to buy it on Wii.
Overall I feel it's lame to just say "better graphics" as manner of cosole preferance, however I think this could be one of the cases where it may matter. I only offer this because historically the RE series has a very substantial element to the game when it comes to the art. The gameplay itself is enhanced by the lighting effects and things that the game uses. So it may be something to look at. However, with Mikami not involved with this one, and if the art direction borrows to much from the movies, than I really wouldn't consider it a factor at all. I'll try to demo this when I get home (AFTER HALO WARS!!!) and I'll let you knoe if my opinion is swayed at all.
"Let justice be done though the heavens fall." - Jim Garrison
"Ask not your horse, if ye should ride into battle" - myself
