Being able to edit your Visual Studio generated projects is one of the fundamental goals of MSBuild. Being able to edit your project file to customize and extend is not something that just happened to work :) MSBuild and Visual Studio 2005 were designed right from the start to enable you to do this. If you ask me, this is the "essence of MSBuild"
So let's say you are working on your project, and have your project loaded in the IDE - What's the easiest way for you to be able to quickly drop into the MSBuild project file (either .csproj or .vbproj) so that you can edit the project to customize your build?
Pretty simple - if you are using one of the builds past the June CTP, you can do this in two steps.
1. Right click on your project in solution explorer and select Unload Project
2. Right click on the project (tagged as unavailable in solution explorer) and click "Edit yourproj.csproj"
It's that simple. No more notepad. No more File->Open->blah->blah->blah. Besides, you get full inellisense based on the MSBuild schema! Wait - there's something better. We will not touch any of the customizations you make to your projects. Customizations will work inside the IDE as well as from the command line - but we will not mess with your changes!
[Author: Faisal Mohamood]