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
• Multiline Comments
• Intellisense completion support for variables, functions, mixins, and keywords
• Intellisense completion support for CSS syntax

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

• Error integration

You can grab the extension from the Visual Studio Gallery

If you are curious about what's coming next you can take a look at the road map for the project.