Lately, Wii games are letterboxed in 4:3. There is no reason for it I switch from widescreen to 4:3 for the increase in visual quality, then games like ARF and Other M force it... I think the devs are too lazy to design for two perspectives, seriously.
Well, it may be hard to accommodate both, but it can also be due to wanting a more cinematic approach. At any rate it's a reason I wanted to get a widescreen TV, a 14 inch TV is small enough as it was but it's effectively smaller when the top and bottom are disregarded.