I know how Rolf feels. I think the cube also needs some exclusive titles anyway. Hopefully, if the PS2 version won't be released until a year later, then that means RE4 won't have to undergo cross-platformititis like Deus Ex Invisible War did.
Anyway, from what I heard, Viewtiful Joe is still meant to be played on the cube: it runs and looks the best on it, period. The PS2 version is for the guy is isn't willing to pay 70 bucks for a used cube and play it right (not to bash the PS2).
So, most likely RE4 on the PS2 will also be the poor man's choice. No sweat coming from me 🙂