UPDATE (4 Dec 2013)
There are two other routes that effect San Bruno and either are being discontinued or modified.
This route currently goes from Colma BART to Skyline College. The alternative route suggested is 121, which serves Colma BART.
Currently goes from Serramonte Shopping Center to SSF BART, San Bruno BART via Huntington and terminates at Airport/Linden. Beginning 26 Jan 2014, this route will no longer go between Serramonte and San Bruno BART via Huntington Ave. The modifed 133 will run from San Bruno BART via Sneath, El Camino, Spruce and end at Airport/Linden. The 131 will replace a segment that ran into Serramonte Center. It will run between Serramonte & Airport/Linden.
Well we have all gotten used to the first phase of the new service plan SamTrans. Routes 390/391 were discontinued and merged into one route (ECR), which dropped San Bruno BART from its service. Route 140 saw some minor adjustments when some school runs were transferred to a new bus route (but the school day run to Parkside remained). Come January 26, 2014, the second round of changes takes place that involves routes ECR, 140, 141 and 398.
Good news! The ECR will be coming into San Bruno BART. Service was dropped when 390/391 were discontinued but obviously complaints from passengers and perhaps city leaders lead to the change. I suspect senior citizens were the loudest since it required a longer walk from El Camino Real to Tanforan. Now for the bad news. Direct ECR service to Millbrae BART is being discontinued. Right now they pick up and drop off passengers on the east side (transit center). The problem was the long traffic lights getting into that area and likely low numbers of pickups. And if you came up from the Caltrain side, a hassle to go all the way up the stairs, cross over, and then down. While it is longer walk for people getting to Millbrae BART southbound (you have to cross the street), for northbound you just walk out to El Camino from the west side of the station and pick up a bus there.
The major change is adding the San Francisco International Airport AirTrain stop at the car rental area. That means schedules will be revised to include this stop. No word on whether this is will be a limited run, all runs weekdays and weekends or some combination. Part of the reason, I suspect, is that airport workers who use the SamTrans/BART pay a lot on the BART end (there is a surcharge when exiting or entering BART from SFO). This would be a lower cost option. Also it allows travelers coming into San Bruno to use the bus to get to downtown area.
San Mateo Ave service is being dropped (which drops also the Angus/Third Street run) except for select trips (school days likely) as well as most of Jenevein. The route will realign on San Bruno Ave for more direct service to Crystal Springs area.
This limited route will run between Redwood City Transit Center and San Bruno BART via SF International Airport. The KX was going to do this (with a run into San Francisco) but they decided to split this section off.