What mystery tech company is moving into new 10k-capacity San Jose office space?

Personally, I think Microsoft or Amazon (mentioned as possibilities in the article) are good guesses. I can't think of many other tech companies large enough to want space for 8-10k employees that don't already have headquarters in the Bay Area. Maybe Salesforce has decided to move out of San Francisco?

Or maybe someone else on one of these lists?

http://en.wikipedia.org/wiki/List_of_the_largest_software_co...

http://en.wikipedia.org/wiki/List_of_the_largest_information...

http://en.wikipedia.org/wiki/List_of_largest_Internet_compan...