It's an amazing testament to just how successful Sony was with the PlayStation 2 that eight years after its launch the console is still selling. And, not in small numbers either as testified by Sony's announcement that it has now shipped 50 million PS2s in North America. That is just about one PS2 for every 134th person on the planet, give or take a console or two either way.
Worldwide sales figures sit at around 140 million, which is equally impressive. Of more note than the almost ridiculously large number of consoles sold by Sony, though, is how many fewer its rivals of the same console generation shipped. The Gamecube managed a comparatively paltry 22-odd million worldwide sales, and Microsoft's original Xbox didn't do much better, with about 24 million units shipped.
Moreover, both of those rivals to the PS2 aren't seeing what could be called roaring sales, whereas the PlayStation still manages to pull in consistent sales despite its age. No doubt helped by the surprising (albeit ever decreasing) number of games still developed for the platform.
No doubt Sony will be hoping the PlayStation 3, currently in the 17 million units shipped region, will go on to equal, if not beat, its predecessors imposing legacy.