Old news I posted this in the correct forum. After a good day fiddleing around and reading the browser specifications I now know what is added on a css level.
hasLayout has been removed. CSS2.1 supported as well as gernerated content.
Really big push for Microformats in a new feature called webslices. It basically lets you take part of a dynamic page and it is updated in browser bar. Good example is Ebay (current bid infomation) and Facebook (see freind status changes) with out leaving the page your on.
Another new feature called activites. Lots of use for this, good one that I seen over at the MSDN was to select a physical address and right click>activities>map. This will then let you see where it is located in a popup menu. Also you can publish straight to facebook or blog by selecting the content. As well as lots more features.
Developer tool bar that rivals firebug and web developer built in! Also you can emulate IE7 and IE6 quirkes mode.
IE8 atm is really buggy. Padding on list item is really bad. AIR crashes CSS support is not there yet at Firefox and Saffari level but its not that far off.
Overall good step my IE and when they iron out the bugs it looks like a really good browser.