The above link is to a topic/string I started seveal months ago. Although there have been no new entries, the information is essentially the same.
I did contact Don Willems, a GM employee who is on this forum, about this same issue in the past few weeks, hoping that there had been new developments. In particular, I was inquiring about a modification of the driver's side power seats in the SLT-2 models. He actually checked with the engineers at the Lansing plant and their response was not what I wanted to hear. They related that the seats in their full rearward position could not be increased to accommodate additional leg room. They cited the fact that the seats would have reached their physical limitations at that point. They also stated that if the seats were moved any further to the rear (if that were even possible) it would bring into question Federal standards pertaining to the Air Bag settings and tolerances. They stated that the system would have to be modified for safety purposes if there were changes to the rearward spacing between the seats and the Air Bags.
Good luck. If you hear anything additional, please let me know.
You are welcome to make additional inquires because others may have obtained more current information on this issue.