SassyStudio provides a small amount of integration with Visual Studio to the experience using SASS / SCSS a bit friendlier. Here's what we provide so far:

• Syntax Highlighting
• Outlining
• Generate css file on save

In the near future I am planning to add support for the following (assuming VS/Web team doesn't add it first):

• CSS Editor integration to get intellisense / syntax highlighting support
• Intellisense support so you can get completion for variable names, function names, mixins, css classes, etc
• Error integration
• Multiline comments

You can grab the extension from the Visual Studio Gallery