We were joking with someone at the Web 2.0 conference this year about whether they should rename the conference next year to Yahoo 2.0, since the company seems hell-bent on scooping up every popular Web 2.0 company. It’s becoming less of a joke. Today, Jeremy Zawodny announces that Yahoo has acquired del.icio.us, the social bookmarking start-up that helped popularize tagging. Fred Wilson must be happy. Yeesh. Who’s next?