I have previously written a short essay, or possibly a rant on "develop and release straight out of version control" or "release in versioned lumps of code, with the development being separate".
That whole thing just jumped to the fore-front of my mind, as it seems that SLIME has changed under my feet again (no, I didn't intentionally upgrade SLIME, but it seems as if I need to stop getting SLIME via Debian and instead pull it myself, so it stops changing when the rest of the system upgrade; I also need to downgrade the SLIME I have installed as whatever I run now is less functional (for me) than what I ran prior to the last upgrade).
I don't know if things would be better or worse if "package and release" was the dominant paradigm, though. It'd probably cause less friction with an auto-update system that is tailored to packaged and versioned releases.