New Language Capabilities in C#, VB 4.0 and F#
New language features bring C# and VB closer together in functionality while F# is a language that allows for building components that take advantage of parallel computing enhancements.
ASP.Net Web Forms 4.0 and Web Deployment in VS 2010
ASP.NET 4.0 Web Forms give developers more control over viewstate management, generation of IDs in the context of data-bound controls, and HTML generated by some template-based controls. Additionally, new provider models for pluggable components and a finer control over the linking of external script files through the ScriptManager control. Web Deployment enhances the process of moving a website though development, testing, quality control and live distributions.
ASP.Net Asynchronous JavaScript and XML (Ajax) 4.0
This group of interrelated web development techniques is used on the client-side to create interactive web applications is now integrated into the .Net Framework 4.0 and VS 2010. With Ajax, web applications can retrieve data from the server asynchronously in the background without interfering with the display and behavior of the existing page.
ASP.Net Model View Controller (MVC) 2.0
MVC provides a structured model that enforces a clear separation of concerns within applications, and makes it easier to unit test your code and support a Test Driven Development (TDD) workflow. It also helps provide more control over the URLs you publish in your applications, and can optionally provide more control over the HTML that is emitted from them.
Entity Framework 4.0
4.0 introduces new features including Persistence Ignorance, T4 Code Generation, Lazy Loading, Plain Old CLR Objects (POCO) Change-Tracking, Better N-Tier Support with Self-Tracking Entities, Model-First Development and Code-Only Development
.Net Data Services 1.5
Integrated into VS 2010 is this framework for developing Representational State (REST)-style interfaces for working with collections of structured data. Using an entity model you can seamlessly create a WCF service that consumes both SOAP and REST interfaces.
.Net Rich Internet Application (RIA) Services
.NET RIA Services simplifies the traditional n-tier application pattern by bringing together the ASP.NET and Silverlight platforms. RIA Services provides a pattern to write application logic that runs on the mid-tier and controls access to data for queries, changes and custom operations.
Windows Presentation Foundation and Silverlight in VS 2010
Enhanced designer integration in VS 2010 assimilates the new capabilities found in WPF and Silverlight 4.0.
Windows Workflow and Communications Foundation 4.0
Along with many performance and efficiency improvements there is now a seamless integration between Windows Workflow Foundation and Windows Communication Foundation and unified Extensible Application Markup Language (XAML) model
Managed Extensibility Framework (MEF)
This is a new library in the .NET Framework and integrated into the VS 2010 IDE that enables greater reuse of applications and components. Using MEF, .NET applications can make the shift from being statically compiled to dynamically composed.