If you check Wikipedia, it lists the destinations that V Australia has applied for:
http://en.wikipedia.org/wiki/V_Australia
The airline has also expressed interest in flying to Japan. Since then, Virgin Blue have applied to the United States Department of Transportation to operate services to and from Kingsford Smith International Airport (Sydney) to Los Angeles International Airport, San Francisco International Airport, Seattle-Tacoma International Airport, McCarran International Airport (Las Vegas), and New York JFK International Airport.
I wouldn't be surprised if you see a triangulation of the LAX/SFO/LAS services somehow - eg SYD-LAX-LAS, SYD-SFO-LAS... or, alternately, to make a daily LAS service worthwhile - send it through to JFK ie daily SYD-LAS-JFK. I doubt V Australia would be able to fill a daily B773ER to either JFK (I know it wouldn't go direct to JFK anyway, but work with me here) nor LAS - so a SYD-LAS-JFK may well work quite well - leaving the SYD-LAX and SYD-SFO seats all open to be sold as point to point, rather than having a percentage taken up by guests connecting through to JFK.
As for the SYD-PER-SYD (if it does happen), they would be rostered day trips out of SYD I would imagine - not a continuation of the LAX trip.