There have been some good points made already in this thread, here's my view which does in part mirror others.
League is my fav sport and the eels my team, but I also have a great deal of time for union and have always liked soccer as well.
I think in terms of soccer in Australia, will always struggle, until we can see regular top line soccer in this country. Lets face it to see the best play, we must watch TV at the same timeslots some of us have been staying up to watch in recent weeks. To watch the english, spanish, german or italian leagues. While this is the case soccer will struggle to get a bigger foothold in Australia.
There is no doubt Australian's don't mind soccer, in fact I would say most like it, but there is only a short window very four years in which the nation takes any great notice. Going through Asia to qualify will help because it will mean playing 6 games with our full squad as opposed to the current 2. Australians every year watch the very elite on a regular basis in league, union and afl, soccer can't compete with that. The success of Australia at the world cup will mean more talent leaves our shores as scouts from Europe scour our teams.
The A league was held up as a massive success and in comparison to some of its predecessors it was. But only in certain areas. The added point is it had no competition from other football codes as it chooses to play in summer. In Sydney the FC averaged 19000 (including the finals), 15000 in brisbane, 14000 in melbourne, 11000 in Adeliade, 9000 was the average in newcastle, perth and the central coast. And I'm not sure if anyone went to the NZ games.
You can only watch the A league if you have pay TV, otherwise you must go to the games or a pub. League and AFL have basically a saturation coverage on all forms of media, yet still get very solid crowds, and both have massive free to air tv ratings weekly, while NRL also gets massive pay tv ratings as well.
I think we are a long way from soccer rising to the top, or even getting close on a national comp level. It will battle away with union for attention, but like union only really gets attention when our national side plays another good national side.
The other obstacle Australian soccer needs to overcome is the possibility that the current side is the best we had in aussie soccer, a really good generation between the age of 25 and 33. Probably 18 our 23 will be 30 or over in 4 years. 10 of the 18 will be 34 or older in 4 years so will probably not play in the next world cup. We need some new stars to emerge and only 3 of the current squad are under 25.
So soccer is a sleeping giant, but it will remain a minor sport in oz for years to come except for those moments when we all love to watch, but they are a few and far between and that is the problem.