I googled around a bit and couldn’t find out much about the algorithm they’re using and I can’t really stomach reading their patent filing this morning. If you have any more info on how it works I’d love to hear it. The reading that I did suggests their target market is delivering large files or streaming media. In that case a second or two more latency on the dns lookup isn’t going to matter much for them – it’s really about getting the server delivering the content as close geographically to the user as possible.

Just speculating here, but you might be able to use DNS anycasting to build a CDN if you had a network of DNS servers with the same IP’s spread across the globe and answering differently depending on which one you ask. So the Sydney Australia server will answer with an IP in Sydney when asked about content.mynetwork.com and if you ask the server in Los Angeles it answers with a Los Angeles IP for content.mynetwork.com.

That may play havoc with DNS in general, but if round-robin works I don’t see why that shouldn’t.