I was reading over my girldfriend's VW Cabrio owner's manual and I came across a feature that I found interesting. Though I don't remember what VW's term was, and I don't have the manual here to quote from, the basic concept was as follows.

Using what I assume are the ABS wheel speed sensors, a system monitors the speeds of the drive wheels during acceleration. If the system detects a discrepency between the speeds of the two wheels (as might occur in an open-diff. vehicle when one wheel was on a slippery surface) it applies braking to the spinning wheel, thus effectively sending more drive torque to the wheel with greater traction.

After reading the manual, and with no other information on the system thus far, it appears that it functions very much like an electronic LSD in many respects. I have given it some thought, and I haven't yet determined any disadvantages to this system other than the increased load and wear on the braking system. However, because of its electronic nature, it could be completely tunable and adaptable in real-time.

I am aware that Honda's own ATTS system was not particularly successful (at least in the U.S. market), but although the concept of electronically directing torque was the same, the two systems function in different ways. Perhaps a more simplistic (though properly executed) approach, such as the one VW has taken rudimentary steps in creating, would prove to be a more effective solution.

Just some thoughts.