A release date has been announced:
A few weeks ago we announced that we wanted to take extra time to be sure the new design is great and something everyone will like. We’re happy to announce that we will allow everyone to start exploring the week of July 14th. This means that you’ll be able to opt in and view the entire new site, before it is actually released.
It’s certainly looking different. I’ve not played around with it enough yet to see whether it’s an improvement or not, but I’d expect that (given their performance in this area so far) it’ll be a pretty polished release, perhaps with a few navigational oddities.