"A challenge" to close it even within the first 100 days of his administration.

Obama Guantanamo: Preparing Order To Close In First Week

WASHINGTON — Advisers to President-elect Barack Obama say one of his first duties in office will be to order the closing of the U.S. military prison at Guantanamo Bay. That executive order is expected during Obama's first week on the job _ and possibly on his first day, according to two transition team advisers. Both spoke Monday on condition of anonymity because they were not authorized to speak publicly.
Obama's order will direct his administration to figure out what to do with the estimated 250 al-Qaida and Taliban suspects and potential witnesses who are being held at Guantanamo.
It's still unlikely the prison would be closed any time soon. Obama last weekend said it would be "a challenge" to close it even within the first 100 days of his administration.