New Features for Web Development in Visual Studio 11 Developer Preview

http://blogs.msdn.com/b/webdevtools/archive/2011/09/14/new-features-for-web-development-in-visual-studio-11-developer-preview.aspx

• JavaScript editor is rewritten, and is now based on IE10's JavaScript engine. Many new features are added for the JavaScript editor to support it as a first class citizen programming language, such as go to definition, outlining, brace matching, etc.
• New CSS editor functionalities include new formatter, validator, snippets, color picker, comment support, hierarchical indentation, vendor specific IntelliSense.
• New HTML editor functionalities include source view smart task, better auto indentation, end-tag matching when editing start-tag, server side event handler generation, extract to user control and more.
• IIS Express is now the default website and web application host instead of ASP.NET Development Server (i.e. cassini).
• LocalDB is the default database for Visual Studio 11 Developer Preview. LocalDB uses the same database engine as other SQL server code name "Denali" CTP3 (like Express, Standard and Enterprise), so it supports expected SQL functionality like tables, stored procedures, etc.  LocalDB is sandboxed so one user's interactions do not affect other users.  LocalDB also makes it easy for developers to create and work with multiple SQL instances.
• SQL Server Database Projects - Visual Studio offers a new project type that makes it easy for developers to build and deploy their SQL Server databases.  Developers can quickly and easily add tables, stored procedures, scripts etc. to their SQL Server project and the structures are stored as SQL scripts, which makes it easy to manage the history of the database via source code control and make it easy to deploy the database to SQL Server instances from Express to Azure.
• Publishing for Web Application Projects (WAP) have been updated. Publishing profiles are now designed for team scenarios and are stored into a separate folder, allowing proper version control and usage from MSBuild/Team Build. You can configure your WAP to be precompiled/merged before publishing on the Package/Publish Web tab under the Project Properties.