So what about Automatic Updater which can also take care of plugins and themes, on top of the WP core? I haven't experienced a clash (yet) but I like that plugin's ability to also do themes and plugins. If only because it practically forces the use of canonical-compliant solutions, and discourages dangerously hacked improvisation - the kind Count Basie would frown upon. I'm takin' the A-train to fully automated self-updating sites...