i have the purity IEM's as well, they're pretty nice and i absolutely love the flat cables that have yet to tangle. i got mine from expansys, you can also find them on amazon.uk
and yes, it's not about the proprietary connector, it's about the location of the port. since nokia put it at the top for some reason there's no good way to design a dock for it. also, since wp doesn't rotate into landscape, a horizontal dock would just look weird, even though htc made them for the titan and radar.
plenty of android OEM's make docks for their phones with ports on the bottom, it's nothing apple has patented, and if they were allowed a patent for something as simple as the location of a charging/sync port, the patent system would officially be 9000% useless.
i think there are some generic cradles you can find if you just want to hold the phone upright though.