We finally have a non-welterweight matchup set for UFC 158, and it's between TUF 11 middleweights Chris Camozzi and Nick Ring. Via MMA Junkie:
Camozzi sent Luiz Cane out of the UFC with a decision win at UFC 153 in Brazil. He's built up a good run of form, winning 3 in a row in 2012 by TKO (Nick Catone), decision (Cane), and submission (Dustin Jacoby). This is his 2nd stint in the UFC, after a surprising 2011 release when he lost to Kyle Noke.
Ring was supposed to fight in Montreal at UFC 154 against Costa Philippou, but the fight was canceled following a last-minute illness on fight day. He's recorded wins over Court McGee, James Head, and Riki Fukuda (although admittedly the McGee and Fukuda decisions are definitely up for debate), with his lone loss coming against contender Tim Boetsch.
UFC 158 has 5 welterweight matchups, and this is the first non-WW booking for this card. It's not known if this fight will be on the main card or preliminary card, but chances are this will be a prelim fight.