Seihyouken on 19 January 2009
According to current VGChartz data, 10,303,894 PS3s were sold between January 5th, 2008 and January 3rd, 2009. That was with an extremely underpreforming holiday season and no pricedrop whatsoever.
I'd say that 30 million by the end of 2009 is pretty much guaranteed. If Sony plays their cards right and combines a $100 price drop along with the releases of God of War III in America, Gran Turismo 5 in Europe, and Final Fantasy XIII in Japan, all during Q4 of this year, I wouldn't be surprised if Sony managed to sell as many as 15 million consoles by January 2010.
