It's not exactly a tutorial, but I've been impressed with @nelstrom's growing collection of screencasts at vimcasts.org:
http://vimcasts.org/episodes/archive
Each short video covers a single topic (or a small set of closely-related topics), and the ones I've watched have been informative and enjoyable. The author says that "the aim is to provide something in each episode that you can take away and use," and I'd say he's succeeding.
