Going back to the add-on manager, the updated interface now makes it much easier to organise your extensions with the addition of a plugins tab giving you greater control over how the browser handles all the multimedia content that is now so prevalent on the modern Internet. As mentioned, most existing extensions will need to be reworked to gain compliance with the new version but, given the rapidity with which the open source community tackles these issues, it shouldn't take long for all your favourites to become available again.
The final addition that I've noted is rather more gimmicky than the rest but is no less welcome. It's the new drag and drop interface. Unlike all previous versions of Firefox and indeed every other browser I've used, which show a simple arrow, when you drag a picture or link from a web page onto your desktop, using Firefox 3, a translucent copy of the image or link appears under your cursor. This may not sound like much but, trust me, when in use it just makes life that little bit easier.
So, we've looked at all the new features individually but the key question is whether the whole thing is worth upgrading to and on that note I can categorically say yes, it is.
Ok, it still has a few problems with websites that insist you use Internet Explorer or Microsoft's own ActiveX but these are few and far between and generally should be avoided anyway - ActiveX has always been a bit of a security risk. I also quite like the Quick Tab feature in IE7, which lets you see a grid of thumbnails of all the tabs you have open, and there is no comparable feature in Firefox 3. However, I wouldn't call this a deal breaker. As for the odd problems here or there with performance issues and bugs, well, remember this is a beta version so you should expect a few. When the final version is released hopefully most of these will have been ironed out and then we can all enjoy what looks to be still the best browser available. While we're waiting, though, why don't you logon to our forums and let us know your thoughts on the Mozilla Foundations latest creation.