The Univ. of Vermont sponsored a conference on PHEVs on Tuesday Dec 11.
Here is a link to the web site:
http://www.uvm.edu/~transctr/
and here is a link to the some of the presentations:
http://www.uvm.edu/~transctr/pdf/PHEV_overview.pdf

Nancy Gioia from Ford was a keynote speaker and highlighted Ford's commitment to an Escape and Mariner PHEV around 2009 I think. Her pres is not available on the web yet.

The conclusion was that VT's grid could take 50k PHEVs easily. The utilities are excited. They want to sell that night time capacity.