Tax credit for buying a Prius?

I really like the Toyota Prius and I was planning to buy one in a few years but not right now since my Corolla is still new and in good shape. I now find out that I can get a big tax deduction for buying one, so I may buy it sooner rather than later. According the IRS, I can get a $2000 deduction if I purchase it this year, but the deduction drops to $500 next year, so I had better hurry.