The must-have productivity tool for Visual Studio, ReSharper 4.0 provides solution-wide error highlighting on the fly, advanced code completion, superior unit testing tools, over 30 advanced code refactorings, multiple handy navigation and search utilities, single-click code formatting and cleanup, automatic code generation and templates, and a lot more productivity features for C#, VB.NET, ASP.NET, XML, and XAML.
– Full Support for C# 3.0 and LINQ
– Comprehensive Insight into .NET Framework
– Solution-Wide Analysis
– Code Cleanup
– New Refactorings
– Multiple New Productivity Features
– Smoother Interaction with Visual Studio Ecosystem
– ASP.NET Speedup
You can see a more detailed information about the new features here.