For all their posturing and promises about browser safety, every version of Internet Explorer continues to be substantially less secure than its contemporary competitors. I have no doubt that IE 9 will be the same.
I tried some early beta of IE9. It seemed to be a substantial improvement over earlier versions of IE (not a difficult thing to do), but there's a lot of silly stuff. For example, all the tabs are located to the right of the URL bar, so that even on a relatively high res monitor, they will start squashing after you have about 4-5 of them open. MS claims that they designed it like this with less technically adept users in mind who don't use tabs. In other words, they didn't design it properly in prior versions, users didn't use it, so they designed it even worse so that no one will ever use it. Another fine example from Microsoft of how assuming that your users are idiots will guarantee that your users are idiots.
In terms of UI, it fits in perfectly with Microsoft's long established corporate strategy of trying to copy verbatim from a competitor (in this case Chrome) but somehow managing to screw it up. One thing, albeit small, that really bothers me about the GUI is the back button -
(My emphasis)
Now, beauty is in the eye of the beholder, and not everything appeals to everyone, but this quite simply is just an icon that was too big for purpose that has had a bit chopped off to fit. Here it looks like someone in MS actually sat down and spent some considerable amount of time ensuring that IE9's interface looks like it was designed by a 4 year old.
But really, even if they managed to iron out all the stuff I have mentioned, and stuff I haven't mentioned, you'd have your standard issue run of the mill browser design that everyone else has had over the past 3-4 years. If MS wants people to take them seriously, they need to beyond bad copies of their competitors products and actually make something new and unique. I started using Firefox back in the early beta days when it was still called Firebird, then switched to Chrome because the UI was excellent, then to Opera 10.5 because it combined the interface of Chrome with a browser that was... usable? I think I'll want to see something pretty substantial to convince me that Opera is no longer the way to go.
Where's Welly? I'm waiting for him to pop in and tell us how we're all terrorist-loving relativists for hatin' on IE.