iOS Simulator doesn't load iOS? I've upgraded to Mountain Lion und also upgrade to the latest Version of XCode (V 4.4).

I use the iOS Simulator mainly for Webdevelopment and not for iOS Development therefore I'm not that into this matter.

When I launch the iOS Simulator it takes quite a while to load and the "beachball" is rotating. After 30sec or so the beachball is gone and the simulated iPhone is kinda ready - however, it doesn't show any OS. It's just a black screen!

If I see the iOS Version under Hardware - Version  there is only one available option 4.3.2 (8H7) which is checked.

Moreover when I launch the iOS Simulator and the "beachball" appears my fans go crazy and the computer gets really hot.

Any ideas on that?
Mountain Lion seems to have dropped support for iOS Simulator 4.3. More on this if you check the official developer forums: http://devforums.apple.com

FYI, I'm  also seeing the exact same issues as yours: beach ball and loud fans. I had to kill a process called SimulatorBridge to stop the fan from spinning.