Most of what we as collectors would import are things not available in Oz.
When you can buy locally you will buy locally if you can (and you aren't being extorted) but that isn't always the case. So at the end of the day, the group losing out are always going to be the consumers because not only will it be more difficult to get stuff but I can see those international businesses who do offer their service to deliver to Oz adding extra costs on to cover the time and inconvenience (on top of the GST collection).

How will the govt get their collected GST from overseas? What's to stop a retailer pocketing the money instead of sending it to the Oz govt. Will the consumers parcel then be stopped because of this? It isn't as if the Oz govt can hunt down retailers overseas and force them to pay... can they?
It seems to me it won't be a workable solution in the long (or short) term. How does this method work out cheaper than having someone sitting at the border processing the parcels? What's a few more Oz Post or customs workers in the scheme of things?

And... how will it work on private parcels?

What happens in this scenario:
Say one of you ask me to buy an MP-10 and ship it from here in HK to you. Do *I*as an individual then have to somehow add/collect GST and figure out how to send those funds to the Oz government? Exchange rates/transfer rates and time wasted would make it almost unpalatable.
If I just write gift does that then mean the GST doesn't have to be paid and you can skip the process?

I don't expect answers by the way... these are just some of the questions and concerns I have about how they can ever possibly make this system work.