Easton EA90 SL: Cell bikes have a few of these sets for $600 which seems like a steal.
Pro's: They are 24/28 spoked and slightly aero. 2 year warranty.
Con's: SP, DB, aero spokes will be hard and expensive to get. There is talk on forums of some of these wheels having been built with a dodgy set of sapim spokes; although these have all apparently been rectified by Easton under warranty.
Shimano RS80 C24: PBK have them for $441. I've had a few people reccomend these as good fast wheels that hold up well even under heavy riders.
Pro's: The lightest at 1500g (ish).
Con's: SP, DB, aero spokes. 16/20 spokes scares me a little.
Hope Pro3 on Mavic Open Pro: CRC have them for under $400. I've had Open Pro rims recommended and I have a Pommy mate who swears by Hope hubs.
Pro's: 32/32 standard DB spokes. These 'feel' like they'd be the strongest.
Con's: Warranty may be difficult as I don't think these are sold in Oz. These are the least sexy!

Pro-Lite Bracciano: This seems to be the most commonly recommended wheelset on these forums so I figured I should just include it from the start. Currently $400 from Pro-Lite Oz.
Pro's: Seem to be very well regarded. Standard spokes.
Con's: Can't find much discussion of the weight capacity of these.
I like the idea of the Easton's the best and I'm somewhat comforted by the 24/28 spoke count but they'd also be the most expensive mistake if they didn't work out. Are the Bracciano's really that good... really? Any advice would be welcomed.