A late 2010 law allows executors of the estates of decedents who died in 2010 to opt out of the estate tax, and instead elect to be governed by the repealed carry-over basis provisions of the 2001 Act. This choice is to be made by filing Form 8939, this basis allocation form required to be filed by executors opting out of the estate tax is due by Nov. 15, 2011. An executor must file Form 8939 to opt out of the estate tax and have the new carryover basis rules apply. The IRS expects to issue Form 8939 and the related instructions soon.  But CPAs and executors are still waiting.

IRS Revenue Procedure:  http://www.irs.gov/pub/irs-drop/rp-11-41.pdf
IRS notice:  http://www.irs.gov/pub/irs-drop/n-11-66.pdf