I have a Creative Extigy that I will give Away to a interested developer and a Lexicon Omega Audio interface as well.
The Extigy Driver source code for linux can be found here, this is a multifunction device and is usb 1.1 from my limited research
http://exaudio.sourceforge.net/The Lexicon Omega works under generic windows drivers, there is hope you might be able to make it work with generic HID USB spec. This device is USB 2.0
Anyone interested in working on developing USB audio drive please let me know. These devices will be given away to the developer who works on it
Sean