I believe there is opportunity to contribute to an IRA up to April 2013 and have it count on tax year 2012. It wasn't clear from this question, so I'd like to ask specifically if it is possible to convert a traditional to ROTH in 2013 (prior to April) and have any of the money implications be felt in the 2012 return. There are multiple considerations here, as in income from the conversion as well as limits during the year. I'd like to know what all possible 2012 benefits I could see.
No, sorry. You can deposit to an IRA in '13 but designate for '12 until 4/15.
You have until the tax return due date (including the extension to 10/15) to recharacterize conversions made in 2012.
Conversions done after 12/31/12 are considered 2013 conversions. (And to the future reader - please add 'up till 12/31/13', obviously)