Where is my application name stored in BizTalk 2009?

At the moment I’m taking the first steps in moving the BizTalk Software Factory to the BizTalk Server 2009 platform.

In order to accomplish that I need to look carefully into the ‘new’ project type and structure of the project file used.

One thing I came across was where the BizTalk Application name is stored, because that used to be in the .btproj file. After some research I found out that it is stored in the .btproj.user file.

From ‘regular’ C# projects I know I can find user specific settings in the .user file and one of the things you should not do is add that file to source control for that reason.

Is that different in BizTalk 2009 development and were these settings added to the .user file because they would otherwise invalidate the .btproj file?

Should we add the .user file also to source control now?

At the moment I think we should because it contains vital information. Anyone who knows the rationale behind this decision?