Eh.... The only time I'd consider buying a Rail shooter for the Wii would be if
(A) It has a unique tilt, like co-op or something. Imagine repelling into a building while shooting people, while your friend is outside sniping people and can cycle between 2 or 3 different snipers.
(B) It is cheap, like RE 4. ($29.99)
That's what I'm doing with RE:UC anyway, I'll wait until some disappointed gamer, (there'll be lots) finds out this is just a rail shooter, beats it, and sells it to EB Games. Then I'll pick it up for a good $25.