I just downloaded it and installed last night. Didn't get a chance to check it out until today though. Immediately I didn't like a few things so I came up with a couple quick hacks to alleviate the pain. If you want them you can download them at the following URL. WARNING: I don't know what these hacks would do to IE7 or IE6 because I'm not testing that so if you don't have IE8 don't bother using them or you could possibly screw something up!! You will know you have IE8 if you just downloaded it in the last few days. That said if you're an idiot it's not my fault! (but I would still be able to help you quickly fix any problems if this does occur)
http://www.savefile.com/files/2062979
First hack on the list: SLOW! If it's not slow for you this will still speed it up a bit!
-This is because the genius's that put together the installer forgot to register a .dll, if you unzip the file I packaged just double click "Speed Up IE8.bat". After clicking you will see a window telling you that the .dll registration succeded. Yay! Now try opening IE8 and check out how much faster it has become!
Second on the list: I hate searchbars of anykind, they mess with the space you have to view things and I've just come to be extremely annoyed when I see one because it's usually a result of just clicking yes in a TOS for something you didn't read or it could come from spyware. I'm not saying that's the case with IE8 it's actually already included, but since I'm accustomed to hating them I'll remain conservative. There is no other way to remove this other than this hack. So that said, double click the file "IE8 Live Search Disable". Touchdown that annoying piece of crap is gone.
Third on the list: The menubar isn't movable and you can't get it to move at will with the mouse. But I was able to make it go above the address bar by using this third third hack. This is just my preference and it doesn't really matter, but it looks better. To use the hack click "IE8 Move Menubar above Addressbar"
Congrats, your IE8 is fast and less annoying. And before you say "Use Firefox you idiot!", I use IE8 occasionally for web-site creation and other odds and ends. But most of the time I use Firefox.
Edit: Another annoyance... the accelerator arrow, it's a little blue arrow every time you highlight some text. ANNOYING! I turned it off.