Apple released the 2.2 firmware for iPhone and iPod touch just on schedule. There are quite some neat improvements, espechially in the Maps application, but unfortunately, there's no word on a turn-by-turn navigaiton app yet.
Also, no sign of 3dvu's or Xroad's solutions for the iPhone yet.
Beside that, there is a nice new offline map application, called Navionics Viewer, available in the AppStore. It just features 2 maps yet, so you can consider it a preview of what is to come. Navionics Viewer aims to naval, skiing and hiking users that want to carry their maps, supported by GPS, but offline, with them.
More maps are about to be released in future, but most likely, they will be commercial.