Eventually I am going to purchase either XM or Sirius (which one doesn't matter so much to me). But, should i continue waiting or just buy a unit now?

Is there any hope that GM may release something in the future allowing XM to be fully integrated into the car/headunit itself? Any chance that once the 2009's come out that someone might figure out how to adapt that setup over to the '08s? Or should i just buy a separate Satellite Radio unit now?

Thanks.

I am waiting as I want a factory option to come out also, but does anyone know if it will happen or not?