I think everyone is getting too caught up in this whole "we will go to the WC because we have the 2nd leg home advantage" misconception. The fact is - this doesn't mean shit.
1. Uruguay are capable of hammering the Socceroos 6-0 in Montevideo, even if we stack the defence and have 10 players behind the ball at every point in the game. This only allows the Uruguayans to attack and they will exploit any defensive flaw, not matter how much players are there. In this situation, the home leg will be rendered useless.
2. The atmosphere in Uruguay is daunting and will be difficult for the Socceroos no matter how much they say they are conditioned for it. Sydney will never be able to create this kind of atmosphere - even if Telstra Stadium gets packed out. Furthermore, there will be not one Aussie supporter in Montevideo whereas I can assure you that there will be a legion of Uruguayans in Sydney there to support their country - as there was in Melbourne last time. Again, the home advantage is rather useless.
3. Finally, the 2nd leg home advantage is peanuts compared to Uruguay's attacking and physical presence; and their experience in playing against some of the best national teams in the world and beating them in different atmospheres, conditions and coping with the different styles of play.
In saying this, I have total confidence that Australia can overcome Uruguay - but they will need a lot more than the cohesion, direction and structure that Guus Hiddink has been able to instil in his short reign. By "a lot more" I mean every single Socceroo playing their hearts out while upholding this cohesion and structure. And please don't look at the 5-0 drubbing of Jamaica - not only are they many classes below Uruguay, but the Socceroos played very poorly against Jamaica relative to the way they have to play to beat the South Americans.