Very close to my in depth and unbiased analysis on the RWC predictions thread swiss toni.
Semifinalists.
Here we go, the easiest one first:
All Blacks will beat Argentina. We haven't had such an easy knockout game since we met France in ... nah just kidding... The ABs will not take this game easy. Slade, after a week of practice as the number one will finally turn in the assured performance we are looking for. ABs by 20+
France vs England. I'm going with France because I drew them in the office sweep

France by 7
SA vs Australia. Australia are a big threat - coming back to health at the right time. The Boks are coming out of a match with Samoa that was more like a war. If the Boks maintain that forward intensity they will win. Australia can match it, but not for more than about 45 minutes I think. Assuming the Boks don't leak tries, I think it will be Boks by 3.
Ireland vs Wales. One to watch. Frankly I am picking a number out of a hat. Wales by 7.
Fair enough that you picked Aust, but I think the Boks have only looked poor occasionally due the quality of opposition - and they still won every game while Australia didn't.