From reading the reviews and from what people say on the "app store" forum, the SDK hasn't changed and XRoad has done nothing to really work around it's limitations. This app offers the same functionality as Google Maps except you don't need 3G to use it. There are no T-b-T directions and the maps are not forward facing, but always North facing (with a limited amount of tricky intersections where it will become forward facing). Therefore it appears this App didn't really do much in terms of bringing real gps to the iPhone.
As for not being able to use Google Maps for real gps, that's fine. However, it doesn't explain where the TomTom iPhone app is. TomTom has already developed a real gps app for the iPhone, using their own maps, and had it up and running on the iphone many months ago, but it is still missing in action. So the inability to use Google Maps for real gps is not the major problem - the SDK is the problem.