Facebook.com has pushed a new version of its web UI so I am looking at the code to see what's going on under the hood. The page is pretty much a mess having bunch od inline JavaScript, and many global variables. (at least the JavaScript is at the bottom of the page) What's nice to see though is that most of the content is actually loaded as JavaScript, then parsed and put to the DOM. This is one of the dilema I still have, that I have to serve content as HTML to satisfy google indexing, but really need it in JS for better manipulation and loading. I am not sure where the "hash based" navigation go, since now when content loads in js, there is really no need to keep reloading the whole page. I guess FB needs to sell some old fashion impressions, so changing the hash was not paying enough CPMs :)
It's interesting to see where the design went. Getting rid of the tabs, the pages now look almost like a news site with the "show it to me all" approach. Again, this will definitely make people click more, although gong from drag and rop widgets to tabs and then to just plain page with everything on it almost seems like a degradation :)
Looking at it as a user, I actually like it. I click, and see more. No clicking through tabs finding them empty. The content is nicely organized by priority what people really care about.