You didn’t think the government was going to give us $600 each, did you? Not hardly. Instead, the amount credited to your 2007 taxes will be added on to your 2008 taxes. Or some weaselly variant thereof.
The [unusually complicated, intelligible only to tax lawyers]wording of the bill appears to indicate that if, for example, you qualified for a $1,200 rebate based on 2007, but in 2008 you earned more income and your credit got phased out because of AGI limitations, you would owe that money back. Ouch!