Any taxable amount of the distribution will represent ordinary income for the year that the distribution occurs and will be subject to income tax at your regular/ordinary income tax rate.
If the amount is significant, it could put your income in a higher tax bracket.
Visit the IRS website for 2007 Federal Tax Rate Schedules.
For more on required minimum distributions (RMDs), see Avoiding RMD Pitfalls and Strategic Ways To Distribute Your RMD.
This question was answered by Denise Appleby