I just downloaded and updated to Mono for Android 4.6.7 from 4.6.6, reopened my solution file, and the android project refused to load. VS is calling it incompatible. In the extensions menu Mono for Android has disappeared and there's no longer a Xamarin tab in Options. It appears to have uninstalled the extension. I tried repairing and uninstalling/reinstalling with the installer to no avail (making sure the VS2012 extension option was enabled).
Is this a known issue that will be fixed soon, or am I doing something obviously wrong that I'm missing? It's very crippling.