I've seen a couple mentions about that (Gmail being another site it breaks). What seems to be going on, and I don't have a Win7 machine to test on myself, is that something's causing IE10 on Win7 to incorrectly switch to compatibility mode on the affected sites. If you use the dev tools to switch back to IE10 standards mode, those sites work normally.

I think they should be able to fix that soon via Windows Update. I remember Windows Update made a change a few years ago that was switching all localhost:// addresses to compatibility mode, so there's probably an easily updatable list of sites that this happens automatically on.

IE10 on Windows 8 is not affected.