Support for the empowering innovative user experiences in applications, such as Windows 7 multi-touch, ribbon controls, and taskbar extensibility features are being added to .NET Framework 4 accroding to S. Somasegar, Senior Vice President Developer Division in his blog posting .NET FX 4.

The Surface 2.0 SDK will also be built on Windows Presentation Foundation (WPF) 4 and share a common multi-touch infrastructure and programming model.  

The DataGrid control will significantly improve your experience when building data centric applications.  Soma said, "We are also addressing some of the fundamentals with even better deployment, continuing improvements in performance and scalability, visual improvements such as text clarity and layout pixel snapping, and improved localization and interoperability."

Visual Studio 2010 is undergoing a transformation as well. Some of the editors are being written in WPF. Soma said, "This work has driven some improvements in WPF and the new WPF controls will strengthen your ability to re-skin your application with WPF while leaving the business logic intact."

N-tier development will get easier. "We are providing Visual Studio support for a single solution that spans both the web server and the client tiers with end-to-end solutions around sorting, paging, filtering of data on the client, as well as end-to-end solutions for data validation from declarative data on the database tier all the way through to the client UI."

With connected systems (Windows Communications Foundation (WCF) and Windows Workflow Foundation(WF)) you will express applications in a way that makes sense to the team and business.

  • In WF includes a composable set of workflow styles, a unification of rules and activities as well as improved data binding, scoping, and expression support. 
  • WCF simplifies implementing complex communication patterns with content-based message correlation and support for long-running durable communications.
  • Adding XAML support for declarative service authoring and improved support for REST service authoring.
  • New flowchart designer that makes it easier to rehost the designers outside of Visual Studio.

In addition, new tools make it easier to build WPF applications. 

For more information, see .NET FX 4.