No, it just simply won't be done. First off, the graphics. As huge and beautiful Resident Evil 5 seems to be, the Wii wouldn't handle it.
Another reason might be that most companies seems Wii is for children/people with not alot of time on their hands. That's the reason Umbrella Chronicles is a "lightgun" game. They were going to make it a normal Resident Evil game but they thought "nah, Wii players want easy to pick up and play games!" so they remade it.
Sucks, eh?