There's some synopsis here and on the wikipedia page
Here are the results of the browsers that I have on my work machine (Windows XP). Note that this is a score out of 100:
No surprise that IE, the bastion of web standards, fails so miserably. I'm actually surprised that Firefox is doing better than Opera, since my subjective opinion at the moment is that Opera renders most pages better than Firefox (except the Google ones, which is not much of a surprise since Google funds a large chunk of Firefox development). Also, the first time I tried the test in Opera 9.26, it crashed the browser. And it just crashed again now with Acid3 open.
All these 4 browsers have big releases coming up, so it remains to be seen who become the new king of the Acid hill. Webkit based browsers like Safari seems to be in the early lead with scores of 90/100 floating around...