A little quote from http://channel9.msdn.com/showpost.aspx?postid=367207:
The IE team has been very hard at work on IE 8 for the past several months and they hit a huge milestone last Friday evening. The IE dev team checked in a bunch of code that included several new features implemented in the core rendering engine that enable IE to pass the ACID 2 test! This is great news for web developers: IE 8 is going to be our most standards compliant browser to date.Wow. Better late than never. However, I still am waiting for the days when us web develeopers won't have to work with N browsers open at once and do CSS hacks for IE6. It's not even that much fun, when you think you've got way more work to do just because someone screwed his part.