I have tried IE9 beta and here are some notes on my experience.
News in IE9
Updated icon as seen above.
Here is the top of the frame. Much slimmer than IE8 and there is no text or icon at the very top of frame.
The status bar at the bottom is disabled as default and to enable it right click where you see the home and favorite icons.
The back button is enlarged as it is the most used button and to get the recent pages to go back and forth right click on either arrow.
Drop down menu with tools
Address bar and search bar are consolidated into one box.
No Windows XP support.
Evaluate how add-ons affect performance and disable them easily.
Pin a web page, by grabbing the tab in the browser and drag it down to the taskbar.
Note how the look of the top frame is changed when www.jtbworld.com is pinned.
If you drag and drop to the desktop it becomes a pinned site as default with .website file extension instead of .url. To change from a Pinned Site Shortcut to an internet shortcut or the other way around just change the file extension. To create a shortcut hold down shift before dragging the favicon to the desktop or right click on the page and select Create Shortcut.
Right click on the pinned site and you see the favorites and tasks added.
This also works when pinned to the start menu.
You can click here to try the API to add a website to the Start menu.
<a onclick="window.external.msAddSiteMode();" href="#">Add Website</a><br />
Jump List Commands makes it possible to customize your site to give access to commonly used destinations (nouns) and tasks (verbs) of an application or site.
Thumbnail toolbar commands allows you to interact directly with the site from thumbnail toolbar buttons, without having the browser window in the foreground.
Tabs can be dragged out to a separate window. I like that!
H.264 video support.
TIFF and JPEG XR images are supported. Example
Acid3 test is at 95/100 in the first public beta (and also in IE9 RC) compared to 20/100 in IE8.
What is Working and a Bug
Most things are working and I think the performance is much better.
The online banking sites I use works fine, PayPal and even the IE7pro plugin works. I’ve not seen any problems with AutoCAD, Revit, Visual Studio and a lot of other programs.
With Windows Live Writer I got a problem when wanting the alternate text on images to be empty. This forced this change to the tag title="title" alt="alt" making it not possible to have the alternate text cleared.
At http://www.beautyoftheweb.com you can download IE 9 beta and at http://labs.adobe.com/technologies/flashplayer10/ there is a Flash Player preview release with enhanced support for Microsoft Internet Explorer 9 beta.
Flash Player "Square" preview takes advantage of hardware accelerated graphics in Internet Explorer 9 Beta, utilizing hardware rendering surfaces to improve graphics performance and enable seamless composition.
When IE9 is installed you can visit this test drive site.