Spam AI
In the future, spammers will build a profile of me from my blog, bookmarks, etc., and use that to compose relevant-seeming mail that will make it through all my spam filters. Bummer. The traditional email model of "accept anything from anybody and assume it's all of equal importance" has got to go.
Also, if I could figure out why dreamhost's mail servers only run my spam filter on some incoming mail (not even that much of it), then I'd be a happier person.