Just found these guys by accident: http://www.klymit.com/index.php/
No affiliation, just love any innovations in outdoors clothing department. In short: among the other stuff, they are making inflatable with the Argon (noble gas) vests and jackets (just one model of jacket actually so far), which can be inflated/deflated as you go to regulate the body core heat dissipation. They are claiming about 3 times improvement of insulation compared to the ordinary fabrics at the same weight mark. Also I saw a third party vendors making compatible shells (windbreaker type jackets) for these.

Here is the video: http://www.youtube.com/watch?v=mg0qXTDeeKk&feature=player_embedded

I think it's really neat idea. I believe that in addition to the insulation, the individually inflated vest could also minimize (and regulate) air circulation between the skin and clothing as an additional benefit.