I ran into something very odd this evening when opening up AE:
The application frame was there. The menu bar was there. All of the pop-up windows were there. Everything worked except that none of the application showed up.
A re-boot did not fix the problem but trashing the preferences did. The only change to the system from the last time AE ran fine was the latest iTunes update. If you run into this try trashing the preferences. It has sometimes helped in earlier versions and I'm glad that this was a 5 minute fix instead of an hour of trying things.
And yes, AE and my Mac are up to date as of right Nov 6.