You can now register your interest in purchasing an AirSpy software defined radio dongle on the new AirSpy website. AirSpy is a new software defined radio similar to the RTL-SDR currently under development by the creator of SDR#.
AirSpy promises to be an improvement on the RTL-SDR with its large 10 MHz bandwidth, 24-1750 MHz tuneable range, 12-bit ADC and a programmable Cortex M4F @ 204 MHz on board CPU. In comparison the typical RTL-SDR has ~2.4 MHz of usable bandwidth, a 24-1750 MHz tuneable range and an 8-bit ADC. A higher bit ADC can help in receiving weaker signals. AirSpy is expected to sell at around the $100-$150 mark, with it being on the cheaper end if there is greater interest.