Add a sane deprecation process and this is much less of an issue -- see e.g. the Java language. Sure, it's not ideal to have multiple implementations of the 'sa

Add a sane deprecation process and this is much less of an issue -- see e.g. the Java language. Sure, it's not ideal to have multiple implementations of the 'same' data structure (if a better way is found, say)... but at least you aren't stalling everything and causing API interop issues for years and years.