Should be on every install

This is a great plugin to install everywhere and automatically keep up to date. It lets you get the latest patches and fixes early, before they make it into the main WordPress releases.

Generally, it’s only updated immediately after a WordPress release, to dynamically solve problems that crop up which the numerous beta-testers may have missed. In an ideal and fully updated situation, it does nothing at all, but just having it activated will ensure that problems can be fixed by the core team, ASAP.