Visual Basic Compiler and Language Auto-Implemented Properties
Auto-implemented properties provide a shortened syntax that enables you to quickly specify a property of a class without having to write code to Get and SetAuto-Implemented Properties. the property. For more information, see
Collection Initializers
Collection initializers provide a shortened syntax that enables you to create a collection and populate it with an initial set of values. Collection initializers are useful when you are creating a collection from a set of known values, for example, a list of menu options or categories. For more information, see Collection Initializers Overview (Visual Basic).
Implicit Line Continuation
In many cases, implicit line continuation enables you to continue a statement on the next consecutive line without using the underscore character (_). For a list of all the cases in which you can omit an underscore character, see Statements in Visual Basic.
Multiline Lambda Expressions and Subroutines
Lambda expression support has been expanded to support subroutines in addition to multiline lambda functions and subroutines. For more information, see Lambda Expressions.
New Command-Line Option for Specifying a Language Version
The /langversion command-line option causes the compiler to accept only syntax that is valid in the specified version of Visual Basic.
Type Equivalence Support
You can now deploy an application that has embedded type information instead of type information that is imported from a Primary Interop Assembly (PIA). With embedded type information, your application can use types in a runtime without requiring a reference to the runtime assembly. If various versions of the runtime assembly are published, the application that contains the embedded type information can work with the various versions without having to be recompiled. For more information, see /link (Visual Basic). For an example, see Walkthrough: Embedding Types from Managed Assemblies.
Dynamic Support
Visual Basic binds to objects from dynamic languages such as IronPython and IronRuby. For more information, see Working with Dynamic Objects (Visual Basic).
Covariance and Contravariance
Covariance enables you to use a more derived type than that specified by the generic parameter, whereas contravariance enables you to use a less derived type. This allows for implicit conversion of classes that implement variant interfaces and provides more flexibility for matching method signatures with variant delegate types. You can create variant interfaces and delegates by using the new In and Out language keywords. The .NET Framework also introduces variance support for several existing generic interfaces and delegates, including the IEnumerable<(Of <(T>)>) interface and the Func<(Of <(TResult>)>) and Action<(Of <(T>)>) delegates. For more information, see Covariance and Contravariance (C# and Visual Basic).
Integrated Development Environment
The following sections describe enhancements to the Visual Studio integrated development environment (IDE).
Navigate To
You can use the Navigate To feature to search for a symbol or file in source code. For more information, see How to: Search for Objects, Definitions, and References (Symbols).
Highlighting References
This enhancement enables you to highlight all instances of a particular symbol in a document by clicking that symbol. To navigate between references, you can use CTRL+SHIFT+DOWN ARROW or CTRL+SHIFT+UP ARROW. For more information, see How to: Search for Objects, Definitions, and References (Symbols).
Generate From Usage
The Generate From Usage feature enables you to use classes and members before you define them. You can generate a stub for any class, constructor, method, property, field, or enum that you want to use but have not yet defined. You can generate new types and members without leaving your current location in code. This minimizes interruption to your workflow.
Generate From Usage supports programming styles such as test-driven development. For more information, see Generate From Usage.
IntelliSense Consume-First Mode
IntelliSense now provides two alternatives for IntelliSense statement completion: standard mode and consume-first mode.
Consume-first mode is used when classes and members are used before they are defined. For more information, see List Members.
Sample Applications Visual Basic includes new sample applications that demonstrate the following features: auto-implemented properties, implicit line continuation, collection initializers, covariance and contravariance, and multiline lambda expressions and subroutines. For information about Visual Basic language samples and how to access them, see Visual Basic Language Samples.
Source: http://msdn.microsoft.com/en-us/library/we86c8x2(VS.100).aspx
