I gave a "What's new in MySQL 4.0" presentation at work today. I was suprised that roughly 50 people showed up to see it. Last time I did a MySQL talk, I had about 20. I guess that's a good sign.
Anyway, the presentation is available here. A lot of it isn't too helpful if you didn't hear the auido (me) that went with it, but someone might find it useful anyway.
Part of my motivation for doing that now was that I could kill two birds with one stone. The LAMP column in the September issue of Linux Magazine will be about MySQL 4.0 too.