Gen X, Y or simply google generation

I've finally caught up on my blog reading and found Ben had refered to this Guardian article on the Google Generation. It's just blown my basic world view, I've realised that I am no longer classed as Gen X. Ever since I first heard the term, it was explained that Gen X related to people who were born to about 1984. Now I realise someone's re-classed it and I now am Gen Y. When did this happen, or did my education system just have different definations to the rest of the world?