...Windows Presentation Foundation–based IDE.
.. after you convert a Visual Studio 2008 project to Visual Studio 2010, you’ll no longer be able to open the project with Visual Studio 2008
IntelliSense in Visual Studio 2010 supports two modes: statement completion and the new suggestion mode. Suggestion mode lets you use members before they’re defined. You can toggle between completion mode and suggestion mode using Ctrl+Alt+Spacebar
Visual Studio 2010 provides SharePoint 2010–specific project templates that simplify SharePoint application development. Visual Studio 2010 also provides the ability to debug SharePoint projects. In addition, you can now deploy SharePoint projects directly to SharePoint rather than having to use the old command-line Stsadm tool.
New options under the Premium and Ultimate Editions’ Visual Studio 2010 Data menu let you compare schema, compare data, edit and execute T-SQL statements, and view and synchronize database schema
The SketchFlow feature encourages user input in the design process because the developer and user can sit down and cooperatively create a working model
...unlike earlier versions of Visual Studio, Visual Studio 2010 doesn’t automatically update applications using older versions of the .NET Framework to the new .NET Framework 4—you must explicitly change the .NET Framework to update your older .NET applications to the .NET Framework 4.
To better take advantage of today’s multicore processors, the .NET Framework 4 includes a new System.Threading.Tasks namespace that makes writing multithreaded applications easier.
What's new in Visual Studio 2010
Michael Otey's tour of Visual Studio 2010 in the September issue of SQL Server magazine informs about interesting new changes. Excerpts -