It might be useful for users who don't actually vandalize, but who make what appear to be mistakes, or just pop in to post a few links to their crackpot pseudoscience site.
Or, who write really interesting and high quality stuff on topics that I'm interested in.... Sounds useful to me, but I fear feature creep.
Don't worry, there's a very powerful force limiting feature creep: the laziness of the main programmer.
wikipedia-l@lists.wikimedia.org