Is it installed for you now then?
I just wanted to check that it was initiating the restart. I know when installing updates on Windows you can restart it whenever you're ready, and it'll install them on it's own. But with OS X I've always made sure to let the App Store (or Software Update pre Lion) restart itself. I personally have no clue if telling it later and then restarting it by hand two minutes later would trigger the install... Something I should really look into.