Apple's massive 1 billion dollar North Carolina data center has been the subject of much speculation since it was first announced in June 2009. The new data center was detailed as occupying 500,000 square feet and roughly five times the size of the company's existing center in Newark, California.
Here is aerial footage of the data center from February, 2010:
http://www.youtube.com/watch?v=hDXSSi1qStA
During today's financial conference call, Apple revealed that the data center will be complete by the end of the year and they will begin using it then. Due to the massive size of the new data center, many have speculated that it will represent Apple's push into cloud computing. iTunes streaming as well as wireless iPad/iPhone syncing have been listed amongst the possibilities.
Article Link: Apple's Massive North Carolina Data Center Ready By End of Year