Thank you to Atty Charles Rubin who posted about the news from the IRS on his blog: Rubin on Tax.
Here is the IRS publication: click here
Some things are fairly clear from the website information, and some things are not.
As far as what is clear:
a. The Form 8939 for allocating basis increases is not yet finalized, nor are the instructions for the Form or Publication 4895, Tax Treatment of Property Acquired From a Decedent Dying in 2010 which will presumably also address some of these issues.
b. The due date of the Form 8939 will be at least 90 days after the Form 8939 is finalized.
c. Instructions for how to elect to have the modified carryover basis rules apply will be included with the final Form 8939 and Publication 4895.