.NET 4 will have new types to support building cancellation-aware applications and libraries. The new CancellationToken, CancellationTokenSource, and cancellation exception types provide a cooperative cancellation framework.
Damien Guard of Microsoft’s Data Programmability has posted a rather long list of the changes to LINQ to SQL. While they are still committed to Entity Framework over the long run, this will do much to alleviate the fear LINQ to SQL will be completely neglected in the mean time.
Ed Essey, a Program Manager on the Microsoft Parallel Computing team, wrote on the latest enhancements to PLINQ that are to appear in .NET 4.0 Beta 1 that is to be released soon. Some of them are: “With” Operators Pattern, Execution Mode, Cancellation, Refactoring, Performance Improvements.
ASP.NET 4.0 offers a new mechanism to enable/disable the view-state, controlling it becoming much easier than before. To store their state, ASP.NET controls have used view-state, enabled by default until now. This behavior resulted sometimes in large amounts of data being transferred between the client and the server.
In the months and years ahead, dynamic languages are going to take on an increasing important role in the .NET platform. To support this Microsoft is heavily investing in integration between the dynamic languages and the CLR.
Microsoft has announced the availability of the next generation of .NET Framework 4.0 CTP, Visual Studio 2010 CTP and the new Windows Azure Tools for VS CTP during PDC 2008.
With .NET 4, C# 4 will be able to support co- and contra-variance in generic interfaces. If you are not familiar with them, think of it as the reason why you can't pass an IEnumerable
In .NET 4 types will no longer be restricted to a single assembly. A single type, or part of a type, can be extracted from one assembly and placed into another. Why would you do this? Well first off all, to reduce the cost of including the Office Primary Interopt Assemblies from several megabytes to about 2KB by only including what you actually need.