I did that, but still had the same issue. The start up screen is freezing on "Initializing MediaCore".
With a little more searching, I found this page:
http://helpx.adobe.com/x-productkb/multi/startup-screen-hangs-premiere-afte..., but I don't have any firewall software installed, and removing the QuickTime exporters didn't help.
I did download and install the upgrade to CS6 11.0.2, and now After Effects is opening again. But it's done this before...hang on start up for a full day, and then randomly start working again. So I'm not sure whether the upgrade actually helped, or if it was just a coincidence.
One odd thing I noticed was that when I tried to install the upgrade, I got an error that I had to close the application Adobe QT32 Server, but I had already force-quit AE and didn't see this in my task manager. I had to restart in order to close it so I could install the upgrade. So it seems to be an issue with running the Adobe QT32 Server application, however that works.