Sadly, we haven't got 24 hour drinking; we've got some shambolic half-way house solution (as is New Labour's way). Which is a shame, because hisorically, every attempt to restrict drinking hours has backfired into causing greater problems with drunkeness; this is true across the world (see
A Man Walks into a Pub). Now this doesn't, of course, prove that we will see the reverse, that de-restricting hours will reduce problems - but there is some evidence in this direction. When all day opening was allowed, there were predictions of widespread chaos and drunkeness but, in fact, the reverse happened: there were less problems and alcohol consumption actually fell in each of the next five years.
On a more anecdotal note: I have regularly drunk at a lock-in for the last year, often leaving at three or four in the morning - not once, in all that time, has there been any trouble at the pub.
Alcohol, for the majority of people who take it, is a positive part of their lives. In a free country the government should not be choosing how to live people's lives for them, that is a personal choice.
I do think, though, that the drinks industry should be expected to contribute more to the treatment of alcoholism, and the cost of policing in town centres (which, incidently, would push prices up - the only proven method of reducing alcohol consumption).