Sorry, OP. It doesn't look too good for you right now.

I run this route (xxx-ATL-LAX-SYD-xxx) about once a month, and I have noticed the DL metal has been getting a little less full in the back since March of this year, when DL.dumb started selling codeshares for DJ flights as well on the DL site (usually at significantly lower prices for Y fares).

But, with the northern hemisphere in full summer travel season, and with Australia in school holidays until 15 July, perhaps....