The Tax Policy Center reports that:
Compared to current law, TPC estimates the Obama plan would cut taxes by $2.9 trillion over the 2009-2018 period. McCain would reduce taxes by nearly $4.2 trillion
Moreover,
Neither candidate’s plan would significantly increase economic growth unless offset by spending cuts or tax increases that the campaigns have not specified.
Because neither campaign is proposing a fiscally responsible program, I do not feel that I can endorse either candidate in this election. Our children and grandchildren should not be saddled with debts resulting from our large structural deficit. Each generation should pay its own bills.
I did stumble across an interesting calculator estimating the amount of difference that the Obama tax plan would make for a particular taxpayer:
Alchemy Today Tax Calculator
(While most people will receive a tax cut under Obama's plan, a Gallup poll shows most Americans believing that Obama's plan will result in increased taxes for their household.)