I think Jason is correct about a "plug in option" negatively affecting the image of Hybrids and relating them to the "electric car" days.

But I suppose it just depends on the timing, and who is shopping. Knowledgeable Hybrid owners might want that as an option - I for one vote would love that for my HCH - "top off" the battery at night with a plug in the garage. BRILLIANT !!

I read one story a while back about a "plug-in" hybrid car under development that would be able to drive the first 40 or so miles under electric power ALONE !! That would be simply AWESOME in that most people's round trip commute is less than that. Imagine having a full 120-130 horsepower if you need it but being able to commute on electric only almost every day !! My commute is city street only, so that would be PERFECT for me.