I tried to update Xcode to 7.0.1 today and it told me that I needed to get OS X 10.10.4 or greater (I had 10.10.3). I agreed to that update, but it didn't update OS X and has now marked XCode as being at 7.0.1 in the App Store. However if I go into XCode it still shows 6.4 and lacks the new features like iOS 9 in the simulator.
So I had it do the OS update to 10.10.5 and let it do the reboot and install process. It came back up and it still shows that XCode is at 6.4 in the application itself, but as updated in the App Store.
What gives? Any idea how to get it to actually update?