I like it - I'm going to read through their released source and papers to see what clue can be crimed from them - but they still base the CDN on an untrusted, third-party mirror network out of their control. I still think the path forward to an "open CDN" involves complete control right out to the mirror nodes and, in some places, the network which the mirror nodes live on.
There's a couple of shortcomings - most notably, their ASN implementation currently uses snapshots of the BGP network topology table rather than a live BGP feed distributed out to each mirror and DNS node. They also store central indexes of files and attempt to maintain maps of which mirror nodes have which updated versions of files, rather than building on top of perfectly good HTTP/1.1 caching semantics. I wonder why..