I have discovered the Analog Devices "Blackfin" DSP/controller lately. Using uClinux, you can run "real" software in this chip, with many options for I/O, including Ethernet and audio codecs. Cheap development boards and free software are pretty attractive. I am looking for anyone who is using this technology (or anything similar) in an amateur radio application.
The chip is powerful enough for a full SDR implementation, but I'm thinking more about building an intelligent controller & digital audio interface for conventional rigs.