USAir doesn't have a strong presence in SFO/LAX and it really would not make economic sense to add routes to non hub cities from the westcoast. The only route that could possibly be feasible for US would be SFO/LAX-DCA which they applied for and lost to AS (LAX/SEA). All other routes are well served via the Star Alliance. I believe Delta/Song now operates SFO-BOS, bringing to 3, the number of carriers in the LAX/SFO-Boston market. Delta recently added SFO-MCO (Song) service as well. The trend for the legacy carriers will continue to be deploying assets in markets that strengthen existing hubs.