
In fact the main connection at the moment between Australia and the US is owned (mostly/totally?) by Optus (Singtel).
Telstra have recently announced they are going to build a cable from Sydney to Hawaii and according to this article Telstra are also part of the consortium building this cable... which starts in SE-Asia, but importantly connects Hawaii to US west coast:
http://australianit.news.com.au/articles/0,7204,2
So in fact its Telstra that is building some competition to the existing cable - although I agree entirely regarding the broadband market here.
This new announcement also completes the picture for Telstra, they will have new cable all the way from Australia to Hawaii to west coast US.
Ocean: A body of water occupying about two-thirds of a world made for man -- who has no gills. -- Ambrose Bierce