Sources close to the deal tell GlobeSt.com that the process actually involves five separate closings, one for each LLC created by the joint venture to run the properties. So, in effect, closing talks will be held between the Port Authority of New York and New Jersey and One World Trade Center LLC; Two World Trade Center LLC; Four World Trade Center LLC; Five World Trade Center LLC; and Westfield WTC LLC, which is in charge of the retail.

"The parent company charges back these LLCs to run those properties and so is guaranteed income from the operation," our source explains. Despite the complexity of the deal, the closings are expected to be complete this Thursday.

Then begins a prolonged transition period, our source explains. Roughly 50 Port Authority staffers will be on hand for 90 days to guide new ownership through the daily hassle of running the massive real estate. "At the end of that period, there will be a decision about who from the transition team will remain with Silverstein and who will go back to the Port Authority," he reveals. Spokespeople for Silverstein had no comment about any of the closing's details.