The thing is, I doubt even Nintendo expected to be where they are right now with the DS. Considering that the PSP is selling at similar rate to the PS2 when it first came out, how do we know Sony's business plan wasn't to sell 21+ million units in this time frame? I'm sure they're plan wasn't simply to outsell the DS because that's not how models are created. They're goal was probably to hit a certain hardware number, a certain software number, and certain UMD number. They've definitely failed the UMD number, but the other two I'm not so sure about. I think with the DS, EVERYONE (including Nintendo) has discovered the handheld market is way bigger than anyone imagined.
My Top 5:
Shadow of the Colossus, Metal Gear Solid 3, Shenmue, Skies of Arcadia, Chrono Trigger
My 2 nex-gen systems: PS3 
and Wii 
Prediction Aug '08: We see the PSP2 released fall '09. Graphically, it's basically the same as the current system. UMD drive ditched and replaced by 4-8gb on board flash memory. Other upgrades: 2nd analog nub, touchscreen, blutooth, motion sensor. Design: Flip-style or slider. Size: Think Iphone. Cost: $199. Will be profitable on day 1.
