I was able to get this working in Visual Studio 2010.
Start with Ruslan’s post here and download the 2.0 IntelliSense file. Then, just follow the directions he posted previously here. All I ended up doing was running the following command as Ruslan instructs:
C:\download_directory\rewrite2_intellisense>cscript UpdateSchemaCache.js
As Christoph points out in his comment, make sure you replace VS90COMNTOOLS with VS100COMNTOOLS in UpdateSchemaCache.js before running the above command if you are using Visual Studio 2010.
I did not need to restart Visual Studio. I added the <rewrite> section only to the applicable Web.config transformation files, as having it in the main Web.config breaks local debugging.