We have a nice shiny new website available with tons of information about Internet Explorer 8, included the links to download beta 1 so that you can try it for yourself! Go here to get it: http://www.microsoft.com/windows/products/winfamily/ie/ie8/readiness/default.htm
IE8 has loads of new stuff, but possibly the coolest feature that I have seen in it so far is something called "WebSlices". Basically, it allows you to take a chunk of data from a web page, and place it on the toolbar; like so:
Note, this is not the MSN toolbar or any other add-in to IE8, this is a feature that is part of the main browser. So, let's say that you wanted to keep your eye on an online auction, you just add the info about the current highest bid of the auction to your WebSlice and then keep an eye on the page without actually having to open it every time you want to check it out; all from the WebSlice that you created. By subscribing to the content of the page your WebSlice will keep itself updated with the latest content.