I'd imagine there is at least something to be gained from calculating position/velocity patterns of receivers (stationary on a desk, moving on a road in a car,

I'd imagine there is at least something to be gained from calculating position/velocity patterns of receivers (stationary on a desk, moving on a road in a car, etc) and then cleaning up data based on that. Or perhaps the goal is to use data from dual freq GPS receivers to helping out the continuing majority of single frequency receivers? Or perhaps they are just leaning on fixed base stations in urban areas to "bootstrap" and focusing on the P2P aspect as marketing, plus a convenient permissions grab for backhauling personal location information.