Simple...Sharp the makers of DS and PSP screens already released the technology on their cellphonews in Japan since 2008. Sony & Sharp already agreed on a joint venture LCD manufacturing plant in Japan so there is a big chance of the next PlayStation Phone having 3-D screens too....
http://www.mobileburn.com/news.jsp?Id=9152
http://mydigitallife.co.za/index.php?option=com_content&view=article&id=1047842&Itemid=150
Will the PS3 be the first and most successful multi-million selling piracy & hack-free console of all time?