I didn't get any of the current systems (except the DC if that counts) at launch and I kinda regret it. It used to be that if I didn't buy a system at launch, chances are I wouldn't buy it ever. Sure, there aren't many titles to choose from but nothing beats launch madness.
I will buy a PS3, Revolution, and GBA2 at launch. The rest are wait and see.
Xenon - I want to see if Team Ninja sticks w/ MS first. They say that they will but who knows.
DS - I want to see more unique games for it first. Right now I haven't seen anything that I would consider to be a system seller.
PSP - If Sony allows Capcom to bring over Vampire Savior and any of the other 2D fighting game ports that they have up their sleeves then I will buy one for sure.
Edit: BOE, your avatar is some trippy shit.