Actually, you can contribute to a non-deductible IRA for 2012 and then convert to a Roth IRA in 2013. You can also simply convert in 2013 your existing Rollover IRA to a Roth IRA. In both cases, you will probaby pay lots of taxes.
My recommendation is to do neither even though you could do either one or both.
It's all about market timing, uh, I mean rebalancing, uh, I mean opportunistic rebalancing, uh, I mean short-term opportunistic rebalancing due to a short-term change in one's asset allocation.