The HackRF project initial goal is to build a single wideband transceiver peripheral that can be attached to a general purpose computer for software radio functions.
Uploaded image
The design is FPGA-less. There will be a tiny bit of DSP capability (ARM Cortex-M4), but mostly we're just trying to get samples to and from a host computer.
We are trading resolution and DSP capability for cost, portability, and frequency range. Considering that we'll be able to support oversampling for many applications and that we should be able to implement AGC, it should be a pretty good trade.
From Design Goals 
on the project wiki.
See also Forbes Article reporting: At the ToorCon hacker conference in San Diego Saturday, October 20, 2012, Ossmann and his research partner Jared Boone plan to unveil a beta version of the HackRF Jawbreaker, the latest model of the wireless Swiss-army knife tools known as “software-defined radios.”