When I gave my talk about mapping solutions in Flash/Flex/AIR, one point I made was due to the TOS with Google Maps, you would be unable to use it in an AIR application. Well as of Tuesday, that is no longer true. The Google Maps team just released version 1.8, and this version can be used in AIR apps!
For more information (and screenshots!), read through their snazzy new tutorial on developing AIR apps in Flex Builder.