Write to Apple to request Keywords under thumbnails.
Keywords under thumbnails were a very important part of iphoto for many people. iPhoto 11 saw them moved to the info window making it a lot harder to see at a glance whether keywords had been added to a photo.
If you want to see the return of keywords to thumbnails, please send a request to Apple at the following link. Apple do listen, but only to the masses.
Mac Pro 2.66 Quad - G4 Powerbook, 15", 1.6GHz, 2GB RAM, 250GB HD, Mac OS X (10.6)