The project is a joint venture between Signature Flight Support and Blue City holdings San Jose (which manages Google's planes). The total square footage comes out to be just over a quarter million: 17,000 SQFT for the terminal, 24,000 SQFT for shops, and 240,000 SQFT of hangar space.
If this project is successful, it could mean more companies moving their aviation facilities to San Jose and the airport getting extra attention (may help us nab a few more international flights). Also, if Google execs are flying out of SJC, there is a good chance Google will be sending more of its lower-level employees through SJC as well instead of SFO. This could potentially be a very big win for the airport and the city.