Good question - The games are definitely ready and I actually thought I saw people play the X360 version already (unless they got a pirate copy )
I actually don't know the answer but I would expect that it has to do with grey imports - UK retail is notorious for slashing prices even before they get the game, and therefore demand from distributors that they offer them plenty of reductions or they'll just refuse to put it in the store. As a result, UK retailers get the game cheaper, which creates opportunities for grey importers to buy the game in the UK and then spread it to other territories, hurting the distributors in those territories. So a certain tendency is starting to appear to prevent them from doing that by delaying release in the UK, but that's obviously at the expense of the customer. It's like piracy - the bona fide player is punished for the actions of pirates because everybody starts putting DRM on the games.
