What are the specifics? Well you'll be able to use the $8000 on contracts through April with some expanded income qualifications. And you'll be able to qualify for up to $6500 even if you're NOT a first-time buyer. You will have to have owned your current home for 5 years. This leaves some people out who could really use the $6500, but hopefully it will lead to better inventory for all the first-time buyers.
Check out this news brief from the National Association of Realtors for a break down of changes from the old bill: http://www.mnrealtor.com/AM/CM/ContentDisplay.cfm?ContentFileID=2950&MicrositeID=0&FusePreview=Yes