Table 4-4 on page 82 in CBO’s Budget and Economic Outlook of  shows that the estimates for capital-gains tax liabilities had been lowered to $46 billion in 2004 and $52 billion in 2005, for a two-year total of $98 billion. Compare the original $125 billion total to the new $98 billion total, and we can infer that CBO was forecasting that the tax cut would cost the government $27 billion in revenues.
Those are the estimates. Now let’s see how things really turned out. Take a look at Table 4-4 on page 92 of the Budget and Economic Outlook released this week. You’ll see that actual liabilities from capital-gains taxes were $71 billion in 2004, and $80 billion in 2005, for a two-year total of $151 billion. So let’s do the math one more time: Subtract the originally estimated two-year liability of $125 billion from the actual liability of $151 billion, and you get a $26 billion upside surprise for the government. Yes, instead of costing the government $27 billion in revenues, the tax cuts actually earned the government $26 billion extra.
Oh, yes, "tax cuts for the rich," indeed.