I'm heading off to MIX07 today.
MIX is by far my favorite Microsoft conference, because it "mixes" in a liberal dose of traditionally non-Microsoft folks for a broader range of perspectives. It's probably the only Microsoft conference I'll be attending this year.
If you're attending MIX this year and you're interested in meeting up, shoot me an email. I'll definitely bring lots of stickers.
I also set up a Coding Horror Twitter stream for MIX related activities, and I'll try to keep it updated throughout the conference, barring any performance meltdowns -- for example, right now Twitter's static asset server appears to be down, so no images or stylesheets appear.