Here is a link to a FAQ that a lender had sent me when I inquired about how the program works.
http://info.ranwc.com/events/homebuyer%20tax%20credit%20--%20Q&A%207-29-08.pdf
Seems that 1st time buyers will be able to get a dollar amout refunded to them come April 2009 if they utilize the credit. The total amount of the Tax credit will have to be repaid at 6.67% a year over 15 years.