And for the whole battery life argument:
Unless it's plain terrible, battery life has little effect on the popularity of electronics. Apple's iPod Mini gives me maybe 6 hours MAX in my experiences, and I still love it due to its simplicity, portability, and ease of use. I just have to remember to charge it every day.
And still, considering the PSP has a crapload of moving parts and features, 4-6 hours average is pretty damn good. I have a feeling Sony will release a better battery in the future, anyway.
No, I'm not a fanboy of either, as I will be deciding which system to buy when they've both had time to establish themselves. Right now I will enjoy my old gameboy advance and Ps2.
EDIT: Woops, apparently the avg is 4-6 hours. My mistake!