The U.S.S. Zumwalt

The Navy has announced that the first DD(X) destroyer will be designated DDG 1000. As the lead ship in the class, it will also be named in honor of former Chief of Naval Operations (CNO) Admiral Elmo R. “Bud” Zumwalt, Jr.
>> Defense Department Press Release [Full Release]

I'm guessing the DD(X) is a take on the DDG designation that the current Arleigh Burke-class destroyers have before their hull numbers, which the DD(X) destroyers will have to. Except they start off at DDG 1000 as stated above while the Arleigh Burke's will stop at DDG 112. Just a bit of a jump.

Image from Globalsecurity.org

>> Globalsecurity's section on the DD(X)