Here's the point I made in the 'is war ever just?' thread, which I'll admit was a bit off-topic there:
I'd say that class is really defined by someone's economic position, rather than their income or lifestyle. By 'economic position', I mean whether or not they own enough capital to live off its profits, either through 'earning' interest, collecting rents or creaming off the profits created by the work of their employees. If someone ticks these boxes, they're in the capitalist class. If they don't - i.e. if they have to work for a living or have to rely on the state for benefits, or scrape a living on whatever they can find - then they're working class. I don't accept the concept of 'middle class' as being separate from 'working class'. Many people in 'working class' manual trades earn more and have more skills than many people working in 'middle class' office jobs, which suggests that you can't base a working class/middle class distinction on wages and upbringing.
So, I'd say that class certainly does still exist in the UK (and everywhere else), and in exactly the same form as it has done since the end of feudalism.