Last month, the Center for Tax Policy put out a report (pdf) on McCain and Obama's tax proposals. At the time, I noted that some of the assumptions they made about McCain's policies, which they got from the McCain campaign, did not match what McCain was himself was saying in campaign appearances. Now they've come out with a revised version, in which they refine their original calculations, but also note discrepancies between what both candidates' campaigns say and what the candidates themselves say, and try to cost out both.
The short version: over ten years, the proposals McCain actually makes on the stump would cost $2.7 trillion more than the policies his campaign describes, for a total cost of nearly $7 trillion over ten years. Over the same ten years, the proposals Obama makes on the stump would cost $367 billion less than the policies his campaign describes, for a total cost of a little under $2.5 trillion. (The main difference between what Obama says on the stump and what his campaign describes is his proposal to levy Social Security taxes on income over $250,000/year.)
Here's a chart showing the effects of both candidates' tax proposals (the ones they describe on the stump) on people in various income brackets, from p. 46 of the report. Note that while this graph shows taxes going up for people in the top quintile under Obama's plan, a more detailed breakdown (p. 45) shows that taxes only go up for the top 5% (incomes over $226,918/year.) People in the 95th-99th percentiles ($226,918-$603,402/year) would pay $799 more a year, on average.
Just something to keep in mind the next time you hear John McCain say: "Senator Obama wants to raise taxes; I want to keep them low. Somebody who wants higher taxes, I'm not your candidate. Senator Obama is."
A longer excerpt from the report at Obsidian Wings, since I can't figure out how to put things below the fold on this site. (An html goddess I am not. Sigh.)