This thing emerged today: http://translate.google.com/translate?u=http://gigazine.net/index.php%3F/news/comments/20100914_ps3_ps2_adapter/&sl=ja&tl=en&hl=&ie=UTF-8
They make a fair point that PS2 compatibility raises system costs, but this would be something only people interested in playing PS2 games on the PS3 will be buying.
Seams fairly feasible, a ps2 doesn't take much space if you take out PSU and the DVD.







