So... had a bit of trouble logging in with IE11 (32 and 64 bit) on windows 8.1 pro. Even tried spoofing UAS and changing the compatability modes.
There were no script errors, and the "information" in the console for FB and g+ are no different than the ones I safely ignore at work.
While it's still in its infancy, I figured I would give you a heads up. Consistently got a 500 response regardless of login method (facebook, linkedin, or usrnm/pw)
I had to download chrome just to login and post :-/
Im guessing IE11s XSS checker or "safe browsing" settings is really going to be a headache in the near future...
Maybe Im just unlucky :-/