use a Panda or a Beagleboard and prototype a device running linux that runs your DCE device.
The nice thing is, once the device attempts to connect, if it receives an INVALID DEVICE, then it can request to create a device for the new device automatically.
It would make a lot of sense to use MeeGo core as the OS of choice, to build a system image, as I have a lot of experience with this, and it would be able to make something that could come up very quickly (especially when using resume from a non-rewritable memory image), to have a fully functional linux system ready for creating an aware appliance.
-Thom