I'm another supporter of the PSP+DS winning ticket. I've had the DS for longer, yes, but I bought a PSP and modded it immediately, and now I'm looking to buy a second memory stick just for PSX games and probably emulators too, so my primary stick would be for the big games.
Yes, I play the systems at their own rates, but I enjoy them both. The people who honestly believe that one system is better than the other is truly missing out.
Edit: And to be honest...what's the point of buying a second system of the same thing you already have? Granted, I have an original-model DS and I think some of the new DS Lites look pretty nice, but I honestly don't see the point now. And mind you, I've had almost every Gameboy unit apart from the colored Gameboy, and GBASP. I'd have to flash the Lite, as I'm too stubborn to get a slot-1 card, and honestly...no thanks.
I'm happy with PSP+DS. =P