I contacted TurboTax to find out what to do if you want to use their software to prepare and e-file your taxes. They told me the following:
“If you plan to claim the credit for a home you bought in 2009, wait until the Form 5405 is updated in TurboTax in mid-March before you file, or before you amend a return you have already filed.”
You should be able to download an update to TurboTax from their website once they update the software. Not exactly sure why it’s going to take them until mid-March to update it, but I’d guess that would still be faster than filing via mail.