Just a note, Windows 7 is not quite ready for IE8, which is not surprising considering that Windows 7 is not even a release candidate yet.
Microsoft has decided to move their parsing engine more towards a standards compliant model which once again will put them in the unenviable position of "dammed if you do, dammed if you don't". They are "dammed if you do" because some websites are not going to work properly. That is not Microsoft's fault; that is the fault of the developer who chose to not create web pages that consisted of properly formed and validated HTML. Here is a blog post that sums it up quite nicely:
One of my favorite features is Web Slices:
Using Web Slices, you can keep up with frequently updated sites directly from the new Favorites Bar. If a Web Slice is available on a page, a green Web Slices icon will appear in the upper-right hand corner of the browser.