Garafa, LLC have released the best GPS suite available in the AppStore at this time: GPS Kit. It features almost everything you would expect from a proper GPS device like tracking, waypoints and even map plotting.
But all this is subject to becoming even better with future releases. According to tech support, the next update will feature GPX import (yes!!!) and they're working on a version that should be able to cache maps so that you have them ready in areas without a network/cellular connection.
Altough this is great and it definedly is a step in the right direction, I'm still missing an application that would allow me to use my own maps AND has waypoint and route import via GPX.
In other news, well, there is no news on G-Map or 3DVU yet ;)