As you may have read, Jetbrains Resharper offers enhanced Intellisense while editing MSBuild files in Visual Studio!
However, I noticed a peculiar problem after I opened my MSBuild file in Visual Studio (which had a .proj file extension)—there was absolutely no Intellisense!
Well, fortunately, I found this article which detailed the crux of the problem: http://consultingblogs.emc.com/stuartpreston/archive/2007/07/29/Using-MSBuild-with-the-Visual-Studio-IDE-and-Source-Control.aspx
Essentially, Visual Studio had no idea how to handle .proj file extensions by default (even though MSBuild recommends the .proj file extension as a standard, go figure….). Therefore, you have to manually configure Visual Studio Text Editor options to handle the .proj file extension using the XML Text Editor with Encoding.
Once that was done, I was able to utilize all of the Intellisense capabilities offered by Jetbrains Resharper within the Visual Studio IDE!