Properly maintained car will not decrease it's mpg until things start falling apart and I read at least 3 long term studies showing that Prius, contrary to popular believe, lost very little as far as mpg go even if hybrid batteries were worn out and lost it's original capacity. I also don't believe gas will go bellow $3, except maybe short term when consumption goes lower than normal, dead of winter maybe when I won't drive much either.
The main reason I would point out $$ savings for hybrids is to debunk nonsense spread out even in popular car magazines that you can't recover the extra cost of hybrid drive train. Some people will take long time to recover , but some will recover extra cost very quickly, especially if you drive a lot in traffic, like I do. I should be breaking even before end of second year. General perception is very important and we need to bring facts and real numbers out so others can make educated decisions instead of following misconceptions and propaganda like the infamous bunch of lies "dust to dust energy report" claiming hummer is more eco friendly than Prius.
FYI Honda canceled Accord Hybrid in its 2008 line up and will bring Accord diesel instead. Do I think this is a stupid idea? Yes I do, instead of improving their hybrid system and rethink the idea of high performance hybrid, they bring back diesel, which at the moment is sold in only 1 car in US, Mercedes, due to not meeting pollution laws.