In case you haven't seen already, as announced here, IE8 Beta 2 can now be downloaded from http://www.microsoft.com/ie8.
Why is this important? Well, Beta 1 was for developers to see the new browser and test their sites with. This beta is about everyone. I'd really suggest taking a look at the IE blog referenced above and see some of the new features that are in this.
I haven't had a chance to install it yet, but it is on my list of things to do in the near future.