Apple has posted an update for iMovie '08 (a.k.a. iMovie 7). This brings it to version 7.0.1. The update "addresses issues associated with publishing to .Mac Web Gallery. It also improves overall stability and addresses a number of other minor issues." If it doesn't show up in your Software Update, you can download the standalone updater here:

iMovie 7.0.1 update

If anyone notices and significant differences (or minor differences, for that matter), take a moment in the comments and tell us about it.