With the advent of 5.00.8239.1000, the site had a major build upgrade (as opposed to a minor build change a la hotfix) and yet another client update to rollout. Normally I would do a client push and slipstream in the client MSI using the clientpatch hack here.
Quite frankly, I was getting a bit tired of pushing the client over the course of a month 😀
So I decided to investigate something that had been bugging me for a while: Automatic Client Upgrade, and why the option was greyed out to enable it was greyed out.
I believe this is a new, as in new to Config Manager 2012, option. We still have the tradition client deployment options either as an automated Client Push or as a Software Update based installation: