You have told us in many forums and blog posts over the last year that the continued corpus of documentation and features in the MSDN library has affected the page weights and site performance and we have heard you. In response, we kicked off a project to address these issues and look at the technologies around ASP.NET AJAX and to use it even more comprehensively across the site. We also dug deep into the TOC page weight and bytes between the client and the server.
We launched this into our labs and iterated until we had the right things in place. The whole of MSDN2 went through a significant re-write of our rendering approaches and we launched those updates into production today. The MSDN library is snappier and the TOC maps to the content quickly and in sync with your library navigation. Overall we are pleased with the results and considering the 10m documents in all the of languages we are hosting today, it is nice to see Microsoft technologies like SQL Server 2005 and ASP.NET continue to differentiate in one of most demanding environments that my team manages.
Here's a little reading trick for you, when you want to toggle the TOC to read the article in the full width of the browser, just press the letter "T" on your keyboard to hide and toggle the TOC control from the page.
Larry W Jordan Jr - Product Unit Manager for MSDN and TechNet Infrastructure Team