With four Firefox versions available at the same time, it's perhaps harder to keep track of the latest new features and changes. But if you want the cutting edge, the Nightly builds is where the action's at.
Firefox 9 is currently in active development and, while most users won't receive it until sometime early next year, if you're feeling adventurous, you can check out what the Mozilla team is up to and grab the latest Nightly builds.
You won't be disappointed, there are plenty of new things in Firefox 9 already, even when compared to Firefox 8 in the Aurora channel and one of the latest additions is a long-awaited revamped download manager.
One of the biggest complaints about Firefox, for a long, long time, has been the windowed download manager. It was very inconvenient and it didn't fit in with Firefox's overall design and user experience.
Finally, Mozilla has done something about it. The dedicated window is gone, rather, a pop-up overlay shows up displaying a list of downloads from the current session.
You can access the new pop-up list from a button that shows up at the right of the tab bar, by default. If you haven't downloaded anything this session, it will not be displayed, making for a cleaner UI.
As soon as you start a download, the small icon shows up, displaying an estimate of the time until the download ends. If you have several of them running at the same time, the estimate for the longest download will be displayed.
But the download list is only displayed on request, by clicking on the ‘downloads’ icon. There are some small design flaws at this point, but the feature only landed.
For example, the icon is completely flat, there's no indication that it's a button. This may be by choice, but it doesn't reveal to users that something is going to happen if you click on it.
This is inconsistent with all of the other user interface elements displayed by Firefox by default. Still, it's a minor complaint and the new download manager is a huge step up from the current one. By the time it lands in the stable channel, any small issue will be fixed.
Note that the new download manager is in the UX branch of Firefox 9, where new UI concepts are tested, and may not end up in the Firefox 9 version that ships to users.