I'm not going to go into the same level of detail with the NetBurner function callbacks and the lower level Ajax details. It really hasn't changed much and if you want to know about that you can watch the video and read the Round two blog post.
In addition to updating to jQuery, the real motivation for round 3 was the Knockout library. Knockout provides support for two-way data-binding, and makes it very easy to implement the MVVM design pattern. If you've ever programmed in C# and WPF you know just how nice and maintainable this pattern can be. In addition to data-binding, Knockout combines some data flow and template techniques that make displaying large amounts of data extremely easy.
This version of the demo takes a single page application approach. I've split the Ajax content over the first two pages and put some About information on the third page. Below is a 4 minute video demo with the web server running in the NetBurner 54441x development board. Source code is available on the NetBurner forums.