TiPB published a post about SDK agreements just yesterday. It addresses some quite interesting issues in the involvement amongst Google (Maps) and their map data providers Tele Atlas and Navteq.
I also mentioned those issues in a comment to a post recently, but TiPB had an in-depth look.
I still can't decide if this is a pro or con TomTom, so read (and judge) for yourself. It is quite interesting and worth reading ;)