Windows has had High DPI mode for quite awhile. Not sure if that will be compatible with the new MPB, but it should help. Too bad most windows apps are fairly broken in high DPI mode.
I've tried using the 125% and 150% DPI modes in Windows 7 on a 1080p display and the support is still rather primitive. My HP ENVY 15 actually shipped with 125% mode enabled by default. Lots of icons, graphical elements, and many fonts become blurry/pixelated when enabled.
I'm guessing a reason we haven't seen high DPI screens from Dell/HP/Sony/etc is partially because the Windows OS doesn't really support it that well just yet. Hopefully things have changed in Windows 8.
