Speaking as an MS employee who has seen how easy it is to put arbitrary combining marks on scripts like Latin and Cyrillic that don't look very good if the font has neither combined form glyphs or knowledge of attachment points, it may be the case that some of these situations that don't look good have more to do with the fact that making it look good typographically when no one put in the effort for the specific case may be simply the price one pays.
Here is a time it came for Cyrillic over five years ago (in that case for Bulgarian): http://blogs.msdn.com/367985.aspx Michael
