One of the things that needs a lot of work, imo, on Windows 8 is the multi-monitor support. For instance, the way the Start Screen only comes up on the same monitor as an already running Modern UI app.
Just a few minutes ago, I have the desktop and Xbox music docked on one monitor, and desktop IE opened with YouTube fullscreen. If you move the mouse from the full screen YouTube to the other monitor it flickers and shows YouTube fullscreen on both ... it's pretty messed up.
Anyone notice that with other sites, or is it a Windows 8 issue altogether?