Interesting to see new applications taking form around maturing web tech such as SVG; I just noted a posting to the JSON-RPC mailing list from the jsolait camp, announcing an example application of a canvas shared between visitors. Not a new idea, but pre-millennial implementations did not do this right on the web with common browser technology, but instead relied on proprietary applications, protocols and graphics formats.
In another five years, will today's proprietary voice over ip, instant messaging and peer to peer video chat services be possible in the same open fashion, right on the web? I hope so.
I think what actually scared me away most, though, was the abundance of poorly spelled (internal) API methods and properties. It felt too sloppy and shaky for my (probably rather spoiled) tastes. Had I found it at the time, I wish I had tried MochiKit instead. By glance comparison, it seems a lot more mature, though again don't take my word for it; I have not tried debugging a large application running under it yet.