I just played on a Win 8 machine today, just to test it. It was an older Dell laptop... about 5 years old... with a low-end Athlon II and embedded Radeon Xpress 1150 graphics. ET played beautifully. I've been testing Win 8 since the last public preview version a few months ago, and it runs well all around on older hardware. I was pretty impressed. Hated the interface, at first, but it's growing on me, and I begin to see what Microsoft is trying to do with Metro. Pretty ambitious, really.
BTW, didn't have to use compatibility mode. ET installed straight out. I was a little surprised at that, as some of the drivers gave me problems on that machine (the vid chip is customized for Dell, so you can't use a generic AMD driver. You have to use Dell's custom driver for Vista. Worked fine after I installed it, though).