We've already disapproved character tags: Star-Wars character tags
Also, based on this, @Null recently removed r2-d2 tag from one of my questions. It means it's in action.
We are slowly cleaning up character tags on a tag-by-tag basis.
Not all character tags are being removed; rather, the consensus based on recent meta discussions is that character tags should stick around if they identify some significant subset of question that a person might be an "expert" in. In other words, it's feasible that someone could know a whole lot about Darth Vader, but not really be interested in the rest of Star Wars. OTOH, it's less likely that someone would only want to answer questions about R2-D2 -- those questions will probably be answered by people who are general Star Wars experts.
It is ultimately a subjective decision, but we've started by getting rid of the "easy" cases: tags with the smallest number of tagged questions, tags that seem to be redundant on every question they're used in, etc. And, it needs to be done slowly and carefull, or we'll end up flooding the front page with old questions.