Your official information source from the .NET Web Development and Tools group at Microsoft.
The web development tools team has been working on an article about a new Orcas feature we call "multi-targeting".
However Scott Guthrie beat us to it and has written up an excellent and detailed article yesterday about this feature so we will just post a link to his article instead.
Thanks to this feature, you can get all of the great improvements in the VS IDE without necessarily having to target the latest framework version as you had to in the past. You can use Visual Studio (or Visual Web Developer) Orcas to target either the 2.0, 3.0 or 3.5 version of the framework. See Scott's article for more details on this and do let us know your feedback as always!