I haven't seen it yet but I'm sure that DRAPED at the NGV will be a must see (in the way that The Golden Age of Couture was 2009's must see). I really should make sure I wander over to the Ian Potter at the same time to see Together Alone (although maybe that will be a bit too much inspiration on the one day?).
Of course, if you're in Sydney, then perhaps you can check out Gene Sherman's Contemporary Japanese Fashion collection on show at the Powerhouse Museum (the website says it's on until Nov 2009, but I heard about it on a podcast in December, so I suspect it's ending in Feb 2010, but call the museum to check if you're planning on going. And then let me know how it was!).