We finally decided to let our Prius be sold to someone else. The $3150 credit and the lure of a one year newer model for only waiting another couple of months was too much for us too justify buying our 2005 model today (it had been delivered and was waiting for us at the Toyota dealership). In addition there were some other tax anvantages for us because of our special circumstances (we can't take the sales tax deduction this year, and getting a new car at the beginning of the year is better if I use it for my business). We let our delivered car go to another buyer and are now on the list for one appx. Feb 1 of next year. It was a very tough decision for us.
I was told that since I paid the AMT last year, I wouldn't be eligible for the tax credit...true or not, it made me feel better about getting the Prius this year...hell, I'm just glad I got it at all!