That's not really it, there's a Gameboy/Color-specific processor that Nintendo included in the Advance but not the DS, but I wouldn't be surprised if Nintendo omitted the ability to play Color and Original Gameboy games on the DS just for the sleekness.

Back on the topic of shooters. Yea, there are a bunch of great, unique
shooters out there, as you said. But then the rest is filled in with WWII shooters and sports games. I'm only exagerating slightly, seriously. I see a lack of originality in most shooters on the Xbox 360.

Thanks for that. A few games missing that I was expecting though.