Jim Mateja writing "GM makes the conveniences of home reachable from car" for the Chicago Tribune describes the Car2U home automation system available in forthcoming automobiles.
At first glance it appears to be not very interesting, after all HomeLink has been around a long time and offers similar functionality. (I use it myself. Readers of Smart Home Hacks should refer to "Hack 57 - Control Your Home From Your Car" on page 206).
However, HomeLink is designed to work with X10 home automation systems. Car2U is based on the much newer, fancier and more robust Z-Wave standard. See the Car2U website for more info, and check out the interesting gateway module at the top of the accessories page. I wonder if it would work as a generic Z-Wave scene controller?