We already have the feature that if a tag is in the top 40 (I think), searches for the contents of the tag search for the tag instead. For example, searching for "java" returns results with posts tagged java. This is good, but on gaming (I don't know about other sites), some of our top tags have synonyms that people are more likely to search for. If people want to know about Star Wars: The Old Republic, they might search "the old republic", but they won't find it because the tag is swtor.
So, I propose that if a tag is a synonym of a top 40 tag, it is also a candidate for searches turning into tag searches. So in the case I just described, searches for "the old republic" would redirect to a tag search for swtor.