Well. Chances are that wii will support bump mapping. It may not support NORMAL mapping or parallax mapping. Bump mapping is just a trick that makes the texture looks like its... bumpy. It does this basically by using the lights to emboss things.
Normal mapping on the other hand looks really good. It truly looks like things stick out.
The reason I think that wii will support bump mapping is that it is a fairly old technique used in tons of games. Iv'e never noticed, but I wouldn't be surprised if gamecube supported bump mapping.
Bump MappingSmall... bumps[the one on the right obviously!])
Steep Parallax Mapping: (notice how its nice and bumpy)
And then there is Normal Mapping... insn't that just b-e-a-utifull: