The OFT has ruled that the pubco tie system does not harm competition in the sector. The ruling comes in response to an official complaint by CAMRA. The BBC has the story. You'll note that shares in Punch and Enterprise have rallied.
You'd be forgiven for assuming I of all people would be preoccupied with this issue - but to be honest I take a pretty robust view on the subject. Independent pub operators who are subject to a tie (like myself) can quantify the effect the arrangement has on their business by considering (a) the difference between free trade and tied product prices and how that effects their bottom line, (b) whether they think their rent would be higher or lower if they had a another commercial landlord that wasn't a pubco and (c) whether they'd have secured as promising a site if they'd excluded tied pubs from consideration.
Whether the tie actually distorts competition is questionable. I'm not sure it does, and suspect the OFT are right. Pubs leased from Punch and Enterprise are still independently operated small businesses - they aren't part of a chain or subject to any central direction. Any suggestion that an industry of free houses only would scupper the big brewers and allow access to market for smaller producers is utterly naive. The likes of ABInBev and SABMiller (and, for that matter, Fullers and Greene King) would still have access to huge marketing advantages and would use their clout to sign up all the newly freed publicans to tempting barrelage contracts.