Since a few days the newest version of Visual Studio has been released together with the new 3.5 .Net framework.
It contains tons of new features such as:
- Multi-targeting support (.Net versions: 2.0, 2.0 and 3.5)
- Built in AJAX support (no need to install an extra package)
- New Html web designer (same as Expression Web) and improved CSS support
- Language improvements and LINQ
- Access to the .Net Framework Library source code (for more information read this post from Scott Guthrie