It is official now, that 65nm Cell and RSX chips are coming to Sony Playstation 3 in the first quarter of the year 2008, and it seems that all the Playstation 3 models will receive this upgrade as well. Also, Sony is currently working with Toshiba and IBM in an attempt to make 32nm chips possible on Playstation 3.
http://www.xuecast.com/?p=208