My #1 excuse is running my car into the ground.

#2 would be clean diesel / lack of hybrid choices.

If I had to get a new car today, I would probably get a Honda Civic Hybrid but I can probably get 2 (or 3) years out of my current car. By then there'll be clean diesels in the US (2009) or the plugin Li-ion Prius (2010 or 2011) to choose from.

Diesels in Europe can easily get the real world mileage of the Prius and they are lot more fun to drive (tiny small engine diesels can beat the Prius). Just in case, diesels have improved ALOT since they were introduced in the US for old timers.