2007 catalog scans are available on 1000steine.de, with pictures of previously unseen summer-release City sets (click to go to the page on 1000steine.de and view full-size images):
Czech LEGO fan site Kostky also has a picture of the new Castle sets for 2007 (via Eurobricks):
I’m very excited about the undead horses, new skeletons (with non-floppy arms) and new accessories (curved swords, round shields, etc.). I can’t tell too much about the castles from this picture, but I like the bone cage on the undead fortress. Wicked!