Silicon Valley Sports & Entertainment, the group that owns the Sharks and manages HP Pavilion, has entered talks with San Jose and Santa Clara about building a 27,000-seat soccer stadium somewhere in either Santa Clara or San Jose. What does this have to do with the A's? One of the sites mentioned as a possible home is Diridon South, though it appears to be down the list a bit.
San Jose City Council member and mayoral candidate Dave Cortese brought up Diridon South as a backup plan if a ballpark doesn't materialize. Considering the cost of acquiring the land - which could be more than the cost of constructing a soccer stadium - it may be a tough sell. The Quakes have only 20 home games per year, which makes it a more difficult anchor for downtown restaurant/bar businesses.
The preferred sites for the stadium are in Santa Clara, all near Great America. They include the overflow parking lot across the street from the 49ers headquarters. Ironically enough, this was once considered the prime site for the A's when Steve Schott tried to move them to Santa Clara a few years ago. The site is also close to a new youth soccer park, making it a prime candidate. Another site is on another existing parking lot at Great America, which was also a ballpark site at one time. Yet one more possibility is land near Mission College. Though the exact land wasn't specified, it may very well be a small part of the college property between the athletic fields/tennis courts and the Mercado shopping center. As a person who grew up in the neighborhood just to the west of Mission College, I can say that this site would bad because of the noise coming from night games and scarce parking.
The upshot here is that if San Jose/Santa Clara can put together a deal to keep the Quakes in the area permanently, it would eliminate one group of potential ballpark non-supporters: those would want to keep the Quakes in San Jose above any attempt to lure a baseball team. Depending on what the proposal looks like, San Jose will need as many supporters of its ballpark plan as it can get.