Not a complete overhaul, but the Challonge layout has been updated. The home page was polished a bit, primarily for new visitors to the site, and everyone will appreciate the new slimmer header.
Tournament tagging has been trashed completely, but digging up old tournaments is easier than ever now that the home page allows for tournament name filtering. If you were among the minority that appreciated the tags, hold tight! There's another option around the corner.