IE8 Beta 1 now available here.
My initial experience with this version was not good. As soon as I viewed my Favorites and started to mouse over the list, the browser crashed. Every time. After the fifth or sixth time, I uninstalled it and returned to IE7.
After downloading a new copy, I reinstalled. It still crashed. Then I started the browser without add-ons. (Right click the Desktop icon and choose "Start Without Add-ons.") No crashes when viewing Favorites.
Ah hah. I went in and pruned down the list of add-ons. I was surprised at how many things had crept into the list. A couple of companies got turned off entirely: InstallShield (2), Symantec (6), Groove Alliance (1). I also disabled a couple of duplicates and some strange things I never used. In the end, I had stuff from Adobe, Apple, Sun, Microsoft, and a few others. After restarting in normal mode, I had no more crashes.
I am not sure of the precise culprit, although Eric Law hints on the IE Blog that it may be the Sonic Solutions Drive Letter Access (part of the Roxio CD/DVD burning software which I got from Dell) and disabled in the browser. I wondered why InstallShield and Symantec needed such a browser presence. I will see what complains as I work and if things seem faster.