I’m currently playing around with ASP.NET 4.0 Beta 2. There are lots of bugs to fight with, but I’m looking forward to RC1, which should be available soon. It’s coming with a GoLive Licence, so when you put your ASP.NET v4.0 bits on IIS7, don’t forget to set your Application Pool to .NET Framework 4.x. Otherwise you will encounter the mentioned error:
Unrecognized attribute ‘targetFramework’. Note that attribute names are case-sensitive.
Looks like the Website Project Template is not working in Beta2, at least for me, or did they remove it completly? However, so far I wasn’t able to do a pre compilation of my website, I can’t find that feature in Visual Studio 2010.