From the TSP:
The President approved the American Taxpayer Relief Act of 2012, on January 2, 2013. This law allows the TSP and other qualified plans to give participants the option to convert their traditional account balances to a Roth balance. The amount converted would be taxable to the participant. We are currently waiting for tax reporting guidance from the IRS and will be studying the actions required to offer a conversion option. After that review, we will make decisions on whether to proceed.