Australia recently ruled that its local (10%) Goods and Services Tax (GST) applies to the majority of online purchases. The big overseas sites, such as Amazon, claimed that it was not practical for them to collect the GST on behalf of the Australian Government. It could get interesting now that that Australia can say "but you have the facility to collect out of state taxes, so why not out of country?"

Presumably there will be a host of new web based startups offering a one-stop tax collection service for all jurisdictions in the world.