Despite your comments I've still only seen people giving times of ~8 hours, as well as both my friends' DS's scoring that. As well, Nintendo gives 10 hours as the max time, so I don't automatically label them at 12 hours/8 wifi. Sadly, despite being available weeks longer to many more people, far less testing has been done--which I find peculiar. (Is there "so long as it gets more than 6 hours we don't care anymore" mindset out there?
)
As for the PSP, it will indeed take two batteries to run for a 12 hour block, but then I say "who in hell cares"? Twelve hours of solid gaming where you have NO access to plugging it in? That's got to account for a good 0.01% of the total amount of time people are likely to spend playing on their machine, barring being a co-pilot.
HORRORS!
I consider pushing the 4 hour block to 6 to be more important, since it's actually dealing in more reasonable blocks of time to go without being able to use an outlet. And that should be accomplishable by kicking down the brightness on even the more stressful games. (Though it might still only make 4 or so with wireless. Needs more specific testing! Hehe.) Which if we want to equalize things, actually puts it at about the DS's brightness level. (At least in every visual comparison I've seen around so far, as well as eyeballing it IRL. The only thing I haven't been able to do yet is compare them side by side. The PSP's luminescence might seem visually greater from the concentration of the larger screen.)
At 8-12 hours I no longer care, and most people never need it either. (But some are perfectly willing to use it as life-or-death reasons to fill the opinions they
want to have.) The PSP would definitely need two batteries to pull it off, but anything under? You can probably get a good bit out of adjusting brightness or picking which games to play for the situation you'll be bereft of that frolicsome AC current.
And since we were already talking about 3rd party battery options, I imagine it won't too long before ones that are not hot-swap batteries emerge. Large capacity rechargables that just plug into the power slot and offer...? I guess we'll wait and see.