Looks interesting..."OpenVizsla is a project to design a device that will allow the capture and inspection of USB traffic that will help with the reverse engineering and debugging of proprietary USB devices, it is created by bushing and pytey of Team Twiizers and iPhone DevTeam fame. This list will grow as the project proceeds!"
Some examples of successful USB protocol analysis -
* Independent drivers for the Microsoft Kinect device
* Linux support for your favorite USB modem or tethered mobile phone
* iPhone sync support for Linux.
* Linux and Mac support for a Windows only Logic Analyzer
For more info go here - clicky click