I have had a number of request to get SlowCheetah working for Azure Worker Roles. I think I have it working now. I have not yet released the support to the download page yet but after the support is verified I will update the release.
If you would like to try out a build which has support to transform app.config, as well as other XML files, for Azure Worker Roles you can find the VSIX at https://dl.dropbox.com/u/40134810/SlowCheetah/issue-44/SlowCheetah-issue-44.zip. After installing for worker role projects you can create XML transforms for app.config, and any other XML file. When you publish to azure, or create a package your files should be transformed.
More info on this on the following issues.
- Support for Azure Projects
- Build error for Azure Worker role if a non-app.config file is being transformed
BTW if you are interested in my upcoming MSBuild book checkout msbuildbook.com
Sayed Ibrahim Hashimi @SayedIHashimi