That's actually where they stored supports for Diamondback during the 2008 season, too. Must be easy to access. Either that, or it's one of the few places on park property that's relatively flat and isn't within guest reach. Or maybe both?
On a similar note, I noticed on Sunday that part of the parking lot to the west of the sign has been blocked off. I wonder if that's a temporary drop-off location for track and supports.
King Cobra lived there for a while, as well as Scooby's Ghoster Coaster.