SANE in conjunction with USB works on the 4100C, 5200C, 6200C, and 6300C model scanners. SANE only speaks SCL to HP scanners. I queried HP with regards to releasing the specs but was told that it wouldn't happen any time soon. HP recently came out with the 3300C scanner. I've received some inquiries about this scanner as to whether or not it will work.
Scanners are perhaps one of the simplest USB devices.
As such, the USB driver is fairly simple when you get right down to it. The driver does not perform any data translations, it merely sends and receives data. This is a very important point because not all scanners understand the same command language. In some cases, not all scanners from the same manufacturer understand the same command language. So, suffice it to say, that the scanner in question may be recognized by the driver, but does there exist an application which can control it is an entirely different issue.