In addition to the feature demo videos above, you can also watch these ASP.NET team member interviews done by Scott Hanselman.  In them various ASP.NET team members talk about a few of the new features they’ve worked on.

There are a lot more features coming with .NET 4 and VS 2010 not covered by all of these videos.  But hopefully the above clips provide a good way to quickly get a sense of some of the new capabilities.

Hope this helps,

Scott