What is it with all these people saying the DS is a Game Boy? It's a DS! Really, don't you think that Nintendo would've called it a Game Boy if they intended it to be so. The SNES played Game Boy games with the use of the Super Game Boy. Does that make it a Game Boy? The GameCube plays GBA games with the Game Boy Player, and last time I checked, it's not a Game Boy. Heck, the Wii can play GameCube games without any add-ons, and it's not a GameCube. See my point?
In addition, the DS has a touch screen, six buttons, and Wi-Fi capabilities. That makes it about as different from the Game Boy as can be. Now, I have nothing against the Game Boy or DS (in fact, I really want Nintendo to make a new Game Boy), but they're two different systems. Yes, they're both portable and by Nintendo, but that's about the only similarities.