Michael Ossmann's latest project is an Open Source transceiver covering 100 MHz to 6 GHz.
It is presumed the RF output from the transceiver may only be a few milliwatts.
Further info - http://greatscottgadgets.com/hackrf/
Surprisingly this proposed Open Source transceiver does not use an FPGA and has a low resolution, however, it points to a future of flexible software defined transceivers at a low price point.
The National Instruments company Ettus Research, founded by a radio amateur Matt Ettus N2MJI, produces the popular USRP™ family of SDR products which are aimed at the high performance segment of the market. Further information - http://www.ettus.com/