Think the biggest difference between 03 (and the late 90's/early 00's) is the Wallabies had won 2 of the last 3 RWC's, were regularly competitive with and occasionally considered as the best in the world (see names: Eales, Larkham, Gregan, Smith, Roff, Horan, Little, Burke, Latham, with a splash of league crossover successes in Tuqiri, Sailor (ish), Rogers and Walker, and basically being a whole bunch more likeable and 'regular' than the brat packs to follow of JOC, Cooper, Beale et al.
Think the biggest part is 20 years of losing means kids don't want a part of it, it's easier to bandwagon on a League team than it is to only have the Wallabies. The lack of international contest doesn't seem to matter in League, it's always been streets ahead of rugby in NSW and QLD for eyeballs and boots on feet. AFL ditto in Victoria.
I don't think the answer is in more established league crossovers, the answer is in getting those kids at the grassroots, which as Burgey pointed out doesn't happen, especially with the NRL gifting contracts to any kid who can tackle and run quick from age 10.
It's also not regularly on FTA tv, which NRL and AFL are, so again, it's just not seen by the masses, and therefore not embraced. Heck, I grew up in a rugby family, but was all league/sokkah until I was about 10 years old as it's what I mostly saw on tv. I didn't get into rugby proper until some family friends got Fox Sports and we'd have regular BBQ's to watch the rugby at their place.
having not live din Aus for 8 years now, I can't comment much about if the 'heartlands' of Sydney's East still even give a toss about rugby, as I assume most of those types died off in the early 00's.
I hope 2027 is a huge success, but also won't be surprised if we do and England 2015 and go out in the pools of our own tournament.
Go the Wallabies.