The crash seems to occur due to a segmentation fault, or more specifically a general protection fault, while calling the saveScreenShot: selector. Why it happens can depend on several things, so it’s hard to say whether a reinstall would help.
In any case, if the screenshot (⌘S) function in simulator causes the crash, there’s hardly anything you can do about it. The best option you have is probably to file a bug report to Apple.
Update:
I just updated to the 8.2 GM, and low and behold, ⌘S crashes for me as well. Although I’m getting KERN_INVALID_ADDRESS instead of EXC_I386_GPFLT.
One workaround, for the time being, is copying the screen and pasting into Preview:
