The way I do it is to try updates at some point when I have a little free time.
Get the new version, but keep the old version. Compile. If it works, sweet, probably ok to keep it. If your app doesn't compile, and it isn't an easy fix, just go back to the old release. Every two or three releases though, I'll take the pain and make sure I'm up to date anyway, usually because the new dmd releases are good stuff.
