Laurence,
Don't forget, though, that these withdrawals wont be the only income you have in those years. You'll have portfolio earnings (interest), some capgains etc in your taxable savings, you'll have Social Security, and if you've been good about socking money away, you may have bigger-than-minimal RMDs (Required Minimum Distributions) to flush out a million dollar+ IRA over the course of your remaining lifetime. When I did calcs on RMDs, I was shocked at how big they can grow, given that your IRA will continue to be compounding and growing, so as you get older the RMDs can really add up.
Thx Martha for clearing up the way these gains are handled. Looks like there is less to this tax cut than meets the eye. Why am I not surprised?