Small world indeed! PM your details if you want to meet up before you leave Sydney. We actually leave end of May but don't get to HK until early Aug. What month/year was your 4yr old born?
We applied to a range of schools in Jan and have actually been offered places at 4 of them. Our two top preferences were AISHK & HKA but they have basically told us it highly unlikely we'll get a spot for 2014 or 2013-14.Think we've decided which offer to take but just waiting on a few more answers. (Even though we're already holding a place at one school think we'll let that go for another school! Expensive exercise)
I know of a couple of people holding places at several schools who aren't deciding which one to til closer to the start if term, so am sure places will cone up. Although that doesn't help you plan where to live etc . . .
Good luck & PM me if you want more info