Dan Gilbert Buys, Fills, and Rebrands One Detroit Center

The Gilbert Empire just announced the annexation of the 43-story skyscraper One Detroit Center. It's not surprising news—Gilbert was identified as the likely buyer weeks ago—but the deal comes with an unexpected caveat. One Detroit Center will be renamed Ally Detroit Center, as Ally Financial—a major tenant in the RenCen—has agreed to make the building its new headquarters.
That's big news. Just a couple months ago, Ally looked ready to move its 700 downtown employees to the cheaper pastures of Southfield Town Center, the office complex from which Gilbert poached Fifth-Third Bank. Instead, Ally is expanding its downtown workforce with 600 employees from the 'burbs. In total, 1,300 people will be stuffed into 13 floors of Ally Detroit Center.
UPDATE (4:15 PM): It looks like Ally Detroit Center will have big, purple sign. There's a blurry image after the jump.