I know that I might be in the minority opinion here, but I honestly feel that if people need government help to buy a house, at tax-payers expense, then they are perhaps not ready to buy a house. Although there has been a definite increase in activity for first time homebuyers because of the tax credit, in the long run, I can not imagine this being beneficial.
People should buy a home when they can afford a home. $8000 should not be why they decide to purchase the largest investment of their lives. I consider that a bandaid on a huge, complicated problem which would be better addressed by dealing with the unemployment issues, not throwing good money after bad.
Just my humble opinion.