WordPress Automatic Upgrade (WPAU) is a plugin that automatically upgrades your wordpress version to the latest files provided by wordpress.org
WordPress Automatic Upgrade plugin update « Techie Buzz
Okay, I was short on time and was willing to take a chance on a minor WordPress upgrade. I had several sites I wanted to upgrade and this looked like it would make the process quick and painless if it worked. For me, the plugin worked and the upgrade was complete in a few minutes. Yea!