I spent 2004 abroad, having never heard the word, came back - and it was everywhere. It was odd, because before that open snobbery was seen as a bit distasteful, but apparently chav was fine, because that mocked working class taste rather than the working classes. Uh, what? Where's the distinction? Pram-face, chav, all snobbish nastiness that judges people on their background, and not who they are as people, and basically implies that to be poor/working class is to be a bit vile, really, and worthy of derision. The label-loving definition, supposedly less snobbish, is still sniggering at people from poorer backgrounds adopting symbols of wealth tastelessly, IMO. In other words, it sniggers at social mobility. And the word is now applied across the board to anyone working class/poor, so it's become frankly snobbish, in a degrading and nasty way.
I always loved Secret Millionaire, despite the squirmy Lord/Lady Bountiful aspects, because it does at least show dirt-poor people doing amazing work to help people in their communities, with no expectation of recognition and with absolute dignity. It's so rare to see that shown in the media - poverty is usually shown as being somehow shameful in itself, as indicative of being lesser, and somehow deserving of a shittier time in life. A person's bank balance is about as helpful in defining their moral worth as skin colour or gender, so why is raging snobbery suddenly fine? Really nice, kicking people who're already trying to keep their heads above water, especially when our society has so little genuine social mobility.