IMO all tracks in an album should have the same year, don't they?
If it's a compilation of trakcs (like a best of) then the ORIGINAL year would change for each track,
but not the RELEASE year of the particular file you're listening to?
Anyway, guess it won't hurt if you implement an average of all years for the album mask... won't make a difference for me

Rating would definitely be cool.
Thanks Trixmoto, you rule man!