As big as Apple's proposed "spaceship" campus in Cupertino is going to be, apparently Tim Cook observed "We're gonna need a bigger ship" to paraphrase Roy Scheider in Jaws. Neighboring Sunnyvale (one of the places I lived when I worked for Sun Microsystems in the 1980s and 1990s) is getting the Apple treatment. According to the San Jose Mercury, basically the official newspaper of the Silicon Valley, Apple is looking to occupy 290,000 square feet of office space, in seven buildings.
The complex, known as Sunnyvale Crossing, is located near Central Expressway and North Wolfe Road. The buildings are decades old but were recently renovated and should meet Apple's discerning taste. This is a 7-to-10-year lease, and at 290,000 square feet, it's chump change compared to the 2.8 million square feet Cupertino "spaceship" campus Apple is building.
However, there could be a good reason for the close-but-not-too-close campus. The original Mac team benefitted from distance between themselves and the Apple ][ team. The Mac team flew a pirate flag over their building in fact. Perhaps Apple will use the new location for skunk works projects. Or maybe it's just to keep the sales and PR teams away from engineering!