It's time for a pile of "Hanselminutes on 9" Episodes, Dear Reader! Recently, I spent a day wandering around building 42 trying to dig up the scoop on Visual Studio 2010 and ASP.NET 4.
In this episode, I sit down with David Ebbo. He shows me a feature I didn't see coming! He takes an older-style ASP.NET 2.0 application and upgrades it to ASP.NET 4. He then enables the GridView with Dynamic Data features...but without adding any references or changing the web.config. He adds validation in seconds. You can maintain legacy apps *and* add new functionality, it seems!