We could pin separate accounts to the start screen all along (other than one or two builds where it broke). It was just difficult to find the exact procedure. I'd be more excited if Notifications for separate accounts was fixed. I haven't tested that yet, but I'm about to. Expectations remain low though. :eck:
And I wouldn't think it possible, but the latest build breaks Live Tiles & Lock Screen counts *even more*. Now the counts always only ever climb. Each new e-mail, the number goes up. Read/delete/whatever your messages, and it never goes down (well, at least not until you reboot your phone). Incredible.