The VTA is undergoing a complete overhaul of their bus schedules [0], in anticipation of the Milpitas and Berryessa BART station openings, which will happen later this year. After that, there'll be express buses from both stations to Downtown San Jose, and, of course, existing connections to light rail.

[0] http://nextnetwork.vta.org

My guess is they're waiting on the Milpitas and Berryessa stations, which supposedly finish later this year.

VTA serves Santa Clara County and the station is in Alameda County; and the next BART station will connect with VTA's light rail and be next to a large transportation center.

They have inter county busses, just see Fremont BART.

Sure, but given they are already planning on making massive changes to the bus schedule as well as light rail, might as well wait for BART to be in Milpitas before doing that, since it's supposed to be "this year".

The 180 series of busses served/serve Fremont BART (haven't lived in the Bay Area for a year).