I don't buy into all the 3D hype these days. But I'm very certain that I'll be getting a 3DS over a PSP2 because the third-party support will likely be solid just like the DS and I prefer Nintendo's first-party over Sony's. Especially on handhelds.
Not right away though. I'm not an early adopter and often times early adopters get screwed over anyway (ie. DS Phat, launch 360s, $600 YLOD PS3s, etc, Phat PSP, etc.) I'll buy one when the 3DS software starts to really hit a stride and new DS software starts to slow down.
I take it that the Japanese are also taking a wait and see approach. Thats what the majority generally does. The early adopters will get the 3DS in its early stages but the early/late majority will stick with their DS for awhile, the late adopters are still buying DS Lites/DSis/DSiXLs in droves (not as much in Japan but in North America and Europe, that is definitely the case) and you'll have the laggards still buying the DS Lite/DSi/DSi XLs after the 3DS is out. It took a little while for PS2 hardware sales to slow down and even longer for software sales to slow down. The DS has a lot of life left in it.







