OMG, just installed the VS 2010 help system and found NO INDEX. In response to your invitation at the end of the video, please please implement an index. Anyone knows that an Index and Search are two different things.
Less important but what I also find amusing is that the TOC in the new system is fixed to the left, whereas I notice from the video that you (like me) prefer to have your solution explorer and such like on the right. So another step backwards 'cos Dexplorer could put the TOC anywhere.
This whole debacle breaks a lot of tenets of good customer-oriented software analysis and design IMO. Did someone say: "Wouldn't it be cool if..."? I do like the way you have implemented the web server app though, and wouldn't mind knowing how you did that.