The Atlantic, Relax, Your Roth IRA is Safe, by Jennifer M. Kowal (Loyola.L.A.):

Given our budget problems, nearly everyone agrees that the federal government must ultimately collect more in taxes, whether by raising rates, closing loopholes, or some combination thereof. … Does this mean you should reconsider your investment strategies? Almost certainly no. Making major financial decisions based on hypothetical future tax policy changes is risky and would be particularly unwise if done to anticipate changes in the tax treatment of IRAs.

That something isn’t fair is no guarantee that it won’t happen. But Congress has bigger fish to fry than Roth IRAs. The wealthiest 1% of Americans own more than 40% of investment assets. The maximum Roth IRA contribution is $5,000 per year, and those making more than $122,000 per year are ineligible (not a particularly enticing target for even the most tax-happy politician). While it’s true that taxpayers may now convert ordinary IRAs into Roths regardless of income, the hefty associated tax bill and time value of money (having the opportunity to invest the money that would have been paid in taxes) makes this a bad deal for most other than the very wealthy, even in light of the future tax-free appreciation. Though the Los Angeles Times recently described Roth IRAs as a “federally sanctioned tax shelter,” the wealthy and their advisers can come up with even better shelters, such as the tax deferral enjoyed on compensation paid in the form of employer funded life insurance policies and stock options. Tapping into these sources or reimposing income limitations on the ability to convert traditional IRAs into Roths would generate far more income than taxing Roth withdrawals. Similarly, deferral of tax on income and gains in non-Roth retirement accounts will also continue.