Ok, some info from yesterday's WWDC keynote.
Sega demoed the Super Monkey Ball, 110 levels, 10$ in App Store.
http://kotaku.com/5014624/wwdc-iphone-super-monkey-ball-set-to-launch-with-app-store
Pangea demoed two games: Enigmo, a physics based puzzle game, and Cro-Mag Rally which apparently is controlled by tilting the iPhone. Both games are 9.99$
http://kotaku.com/5014656/pangea-bringing-enigmo-and-cromag-rally-to-iphone
Digital Legends showed Krull, a 3D adventure game that'll be ready by September.
http://kotaku.com/5014668/digital-legends-bring-3d-fantasy-to-the-iphone
It seems that all devs are praising the platform, and porting games to the iPhone seems to be lightning fast. According to Kotaku, Krull was ported in 4 days, and Enigmo and Cor-Mag Rally took 3 days to port, though they were ported from Mac OS X.
In addition to those, some interesting apps were shown, such as a medical imaging software for checking CT and PET scans. Check http://www.popularmechanics.com/blogs/technology_news/4266929.html for more detail if you're not overly allergic for Apple fanboyism ;)