Hi Steve, thanks for the comments. The blog post that I have is more targeted executing app offline with the integrated build+publish experience. If you are calling msdeploy.exe you can use the new -enableRule for app offline.

We have not yet added support for this rule in our build/publish MSBuild targets. We have not done that yet for the following reasons:
* It requires MSDeploy v3 on the server
* It currently does not support a custom app offline file

I am working with the MSDeploy team to get support for custom app offline files (the feature was implemented, but we had to disable it at the last minute due to a security concern).

@Bert in the next version of Visual Studio you will be able to create a transform based on the publish profile. So if you have a publish profile named "TestEnv" then if a web.config transform with the name web.TestEnv.config exists it will be invoked.

@Benjamin, I agree. I'm thinking that if there was a file named app_offline-template.html (or smtg similar to it) and that is the one which gets converted to app_offline.htm. If there is none then just drop an empty file for the default message.