Clint Ecker of Ars Technica has a good overview of iPhoto’s new features, including changes to the image editing overlay.
iPhoto’s update looks solid. Apple embraced geotagging with this version of iPhoto, and is using it in some unique ways, such as creating maps in slideshows and photobooks of places visited.
iPhoto ’09’s integration of Flickr and Facebook looks excellent. My favorite part is that tags is synced back and forth between Facebook, so if you upload photos and your friends tag people in them, the tags are synced back down to your iPhoto library. I love smart little things like that.