My guess is that if you aren't in 4wd then there isn't any way to provide power to the fronts, the connection just isn't there. So, no, I don't believe this feature will work in 2wd.
The torsen works when in 4wd hi or lo. When in 2wd only the back wheels will receive power.
A real benefit of the torsen is that you can choose to be 4wd hi while on-road, effectively having all-wheel drive. This is not the case with a more traditional 4x4 with a transfer case.
It is a very versitile 4x4 system peforming awesome both on-road and off.