They fixed that speed of light problem? :) We're going to be stuck on 100ms ping times until that is fixed (http://www.wolframalpha.com/input/?i=sydney+to+los+angles+at...)
OTOH, I'm not sure what they will do when Amazon opens their datacenter (if that really is their plan).
We can't (easily) accept payment from US customers (and vice-versa)
That's not really true. Yes, it is more work than "include this Javascript file and you can accept payment" (aka Stripe), but if you are prepared to do some work it isn't that big a deal. Plus there is always Paypal. (Also, most US countries accept Australian payment. Some won't ship here, but that's a different problem)