Same could be said about Usb3. Add in cards don't sell that much, and personally i would hate it to use a addin card for such a thing, plus this is only a option for desktops.
So in the notebook market it boils down to new units, and there intel has the leadership with ~85% marketshare of shiped untis each quartal. My original statement still remains valid, if intel decides to include TB in centrino 80% of all new books will have TB and in 2-3 years the majority of the market will have it. Amd is in that equation a nonfactor. In fact they even could use this to block amd from getting more marketshare, if they agressivly market TB as must have feature.

Regarding conection to the MB, whats the problem with that?
You already do this with all of the hybrid graphic solutions...