http://www.united.com/press/detail/0,6862,53222,00.html
That was from 2005.
I could've sworn they had advertised the extra flights in August last year, right around the same time a whole bunch of XF capacity showed up LAX-SYD. I do know the capacity showed up on August 16, as I have an e-receipt from that day when I booked two seats for us during high season down under (Jan 2007).
I also doubt extra capacity will be added.
Pat