This feedback is related with ID 802020. https://connect.microsoft.com/IE/feedback/details/802020/popups-cause-modern-ie11-rtm-to-stop-running
Using window.open with some 'features' ( defined here http://msdn.microsoft.com/en-us/library/ie/ms536651(v=vs.85).aspx ), we can *sometimes* kill, or give some delay to, our new Modern(Metro? Windows Store?) IE11 RTM.
IE11 won't be killed if we run it for the first time since Windows rebooted, but somewhat later the bug occurs, or not. I don't know the exact condition to make this bug, but it certainly occurs by window.open.
This bug seems to occur not just for me. https://www.facebook.com/groups/win8i/permalink/524602217634378/?comment_id=524620007632599&offset=0&total_comments=5
IE11 for desktop is free from this bug.
Now it seems that the bug can occur only by optional 'name' parameter, whether it is null or not.