For a time there, del.icio.us seemed to be pretty moribund. Recently, there's been a spate of changes including: a new frontpage, secure API access, advertising, and promoting active users. Joshua Schachter, the head del.icio.us honcho, is pretty conservative, but maybe we'll see some interesting new innovations in the tagging arena. Other than developers baking tagging into applications for buzzword compliance, I haven't seen much new in terms of how tagging is designed as a user interface element.