>A new interface is available for those who would like to use it. You can switch it from Account\General settings.
>
>That interface includes a Notifications item in the menu to summarize in one location has related notifications of the site (replies to you, new message directed to you, private message, solution, help, etc.).
>
>The toolbar is no longer applicable and a clean menu is shown. That menu now allows the interface to be diminished more as it locked the interface to its length before.
>
>The top 10 lists are removed and the space is used to make room for a newsfeed includes all kinds of activities on the site.
>
>French is fully supported and you can switch to that from Account\General settings.
>
>On mobile, the right panel is not shown making it easier on small devices.
>
>A full version of this is under way once a few adjustments completed and additional settings for your own in regards to the way this interface works will be provided.

I haven't looked at it in detail, in general it looks good.

One thing that jumps out at me - the borders to the left and right seem rather wide, much larger than the borders at the top and bottom (FF 45.0.2). They do automatically adjust nicely if the browser window is manually resized.