Roth IRAs are attractive for several reasons: (i) in exchange for the nondeductibility of the contributions, the withdrawals are tax-free; (ii) there are no "required minimum distributions"; (iii) you can participate in a Roth IRA even if you participate in an "employer plan." By contrast: (i) distributions from "regular" IRAs are taxed; (ii) beneficiaries of regular IRAs generally must start receiving distributions after age 70-1/2; and (iii) participants in "employer plans" may only contribute to a regular IRA if they are within certain income ranges.
Most wealthy people cannot qualify to convert a regular IRA to a Roth IRA because there is a $100,000 limit on "modified adjusted gross income." In 2010 that limit is eliminated. Additional good news: the tax that is incurred on the conversion can be paid 1/2 in 2011 and 1/2 in 2012.
Example: in 2010 you convert a $1,000,000 IRA to a Roth IRA. Your $450,000 income tax bill can be paid 1/2 ($225,000) in 2011 and 1/2 ($225,000) in 2012.
There are many reasons to consider converting your regular IRA to a Roth, especially in 2010 when the MAGI limit is eliminated. For example, you may—unfortunately—have large losses which you can use to offset the income generated by the conversion, which losses might otherwise go to waste. If you have no other reasons, the benefit of having tax free distributions in the future—in a time of rising income tax rates—is itself enough of a reason to convert an existing IRA or an existing profit sharing plan to a Roth IRA.