In all honesty, two players in the news channel business is too much for the UK - Sky goes along with Sky News for reputational reasons. The BBC has cut the news channels live distinctive hours hugely - it shares with BBC1, BBC2 and World for huge chunks of the day and night.
As CNN found, straight news is never going to be a huge money-spinner unless there's a massive story which runs over an extended period of time, such as the Gulf War. And at that point you need to spend more money covering the thing anyway.
The likes of Fox News etc presumably make cash by supplying highly polarised programming, but God help us all if the UK ever goes down that route.
But then again, BFM TV in France is going from ratings success to rating success with its lively breaking-news-and-debate formula -- and beating many general-entertainment channels in the process.
My point, I suppose, is that there are many possible formats for a news channel and just because one doesn't work, it doesn't mean that another won't succeed.