Here it is in a nutshell:
The new law will extend the $8,000 credit for first-time home buyers for sales contracts entered into by April 30, 2010 and closed by June 30. Further, it has been expanded to include a new $6,500 credit for owners of existing homes who are purchasing a new principal residence. An existing home owner can claim the $6,500 tax credit if they have been residing in their principal residence for five consecutive years out of the last eight. Additionally, the income eligibility limits to claim the full credit amount for both groups of home buyers have been raised to $125,000 for individuals and $225,000 for married couples.