Form 8939 was released on Friday

Here is the announcement.

This is the Form for opting out of the 2010 estate tax, choosing the carryover basis instead, and telling IRS what the asset values are in the estate.  Only the very largest estates need be concerned--I'm looking at you, executor for George Steinbrenner.

The due date is November 15, 2011, and extension opportunities will be limited.  That's because, even though it's a short filing window, it's an overly long window since the date of death for all affected estates.