Command-line build (devenv /build, MSBuild, etc.)

In the comments about a post I made a year ago about devenv /build (here), a person named Peter just a couple weeks ago made the following comment:

When we use IDE to build a project, we have the file(s) checked-out, and IDE will build the changes (checked-out files), will command build do so? I.e. do I need to check in my changes in order to build them? If so, then that's a big drawback for command build.
Thanks,
Peter

Comments on that old post are now closed (maybe because it's a year old?), so I'll answer here.  Peter, I'm not sure I fully get your question, but in general we build whatever's on your machine, be it checked out or not.  This is true whether it's devenv /build or MSBuild.

There were a few other complaints about devenv /build putting up UI.  When this happens, it's a bug (sorry!).  In Whidbey, we will provide MSBuild, which is competely separable from VS and runs without any GUI around (as with NMake, NAnt, etc.).

Chris