Future routing protocols (already under development) that include end-to-end route verification will be the end of it, I expect. "Democratizing" part of the Great Firewall and building it into the 'net itself. Only way around it will be proxying, and that'll risk getting the proxying-IP partially blocked, if it's caught or any of the traffic is deemed "bad", and requires that you can route to the proxy itself in the first place. Won't be entirely immune to circumvention, of course, but will make selective and region-blocks and throttling more common and more precise, and significantly raise the bar for getting around it (which'll probably be illegal nearly everywhere, too).