OK, News 1: Firefox 3.6 Beta 1 is available for developers to try out. It can be downloaded from Mozilla’s FTP. The link’s in this post. Find it yourself.
News 2: Would you like to spice up your Firefox a little? Maybe like adding Tab previews that go with the overall feel of Windows 7? Mozilla has just released Firefox 3.6 Beta 1 Developer version but it’s almost the same as the public version 3.5 except for a few changes: You can add Windows 7 style switching of tabs (which, in case you don’t remember changes with key combination Ctrl+Tab).
This is how it’s done:
1) You need to download and install the developer version. You can download it here (direct link)
Once downloaded and installed, Open it and type about:config. A page will appear confirming if you really want to change the configuration. Click the button. 
Once in the configuration page, type in “browser.ctrlTabPreviews ” in the filter text box and set this property as TRUE (By double-clicking it). You’re done! 
So what does it change? This is what it changes: Try opening multiple tabs and then press Ctrl+Tab to change the tabs and see the effect! It’s just like your Windows 7 Tabs! This is how it looks like:
Did you see the bar opening up and tabs appearing on it with thumbnails of the pages! It looks cool.
So what else is new? Surely you missed a little more: If there are more tabs then can be displayed, you can view them right on your page by pressing Ctrl+Tab and click on “Show All Tabs” that appears on the same window like this: 
You’ll see all of your tabs in the dialog box and you can also filter them like this: 
Now this is sleek! Try out some more stuff and do share with others.
If you missed the download link, here it is again: