The new site is now able to take advantage of websockets!
This is big for real time data in web applications. The current site loads up a page and what you see is what you get. With a websocket, you open a connection to a special server so that the server can push updates to your browser at any time. This is what social networking sites rely heavily on.
Another huge advantage to websockets is how little resources and bandwidth it takes. It sends a handful of bytes vs loading all the page data and associated database connections from a web server. I tried logged in on my phone and the updates from my phone to my browser were pretty much instant!