[berdario]

Oh wow, I had no idea about the unintended consequences of the DMG + App bundle installation mechanism.

Maybe the issue could be ameliorated with a self-updater built-in into the app? Not a separate daemon, but something that by running inside the app, would be able to know what's the path of the old version that should be thrown away.

[lvillani]

Some apps offer to move themselves to /Applications on first launch.

Still, there's the possibility of users clicking "Cancel". Even then, it's a bit more code to write, test and pay for (from the POV of a client).

Wrapping the bundle inside a .pkg instead of a .dmg solves the problem "for free".

[ThePowerOfFuet]

The de facto standard for this is Sparkle.framework, and it's excellent.