Glad you posted for suggestions. Overlap is a big problem.
You may need to bite the bullet and combine some forums, if that makes sense. I lean toward a hardware forum NOT liked to Carrier, and a Software Forum (eg your existing PocketPC) also not linked to Carrier. Why? Because if it IS linked to the carrier, you will end up with duplicate issues in both forums.
1) add a Navigation (GPS, software, Maps, LBS) Forum, maybe subdivided into Installed Software (eg TomTom, et al) and Subscription Services (eg Telenav). Navigation and Location Based Services (LBS) are exploding in importance!
2) add a camera phone subform (that Niknon forum is a real head scratcher).