While checking out the gamesindustry.biz piece that speculates on the PSP's battery life, you might also wanna check out this piece that quotes Sony's latest hardware sales figures: http://www.gamesindustry.biz/content_page.php?aid=5254
PlayStation/PSone
North America: 40.2 million
Europe/PAL: 39.8 million
Japan: 20.9 million
PlayStation 2/PStwo
North America: 32.2 million
Europe/PAL: 25.9 million
Japan: 17.9 million
As usual with Sony's numbers, these are sell-IN figures (hardware sold into retail) as opposed to sell-THROUGH figures (hardware sold to consumers), although the difference is rarely more than a few million.
Those are staggering numbers, in case you didn't know.
-- Z.