When DS first came out I wondered, "Is that screen really necessary?" Fastforward six/seven years. The DS has some of my favorite games ever and I consider it a very important part of my gaming life. Do I still think the second/touch screen is useless? You bet I do!
So far the games I have played I mostly use the normal button controls (Pokemon, Pheonix Wright, blah). When they force me to use the stylus I moan, pull out the stylus, reorient myself on my chair, couch, bed, and think about how much nicer it would be if they just had a godamn analog stick. Often times if I can forgo the stylus and just use my thumbs, and it's actually quite nice. But generally the dual screen and stylus are just big letdowns.
That brings me to my main argument, why do console developers force these gimmicky controls on us. Sometimes it works, I'll admit. Nintendo Wii obviously worked most of the time. But with PSP2 and 3DS coming out, you can't help but feel terrified that you have to pay for these pointless controls that developers stuffed in there just because they thought climbing a vine would be cool with a back touch panel. No, it's not. It conflicts with the normal controls and ultimately pulls me out the game until I get off the vine, then tosses me back in. All this for what? Climbing a vine. Nothing much else it can do (wait, I forgot you can make hills and roll things). Pretty much the only new controls from PSP 2 I like are the right analog stick, gyroscope, and froint touch screen (oh hey R2 and L2 buttons, long time no see! Wait, you're not coming on the PSP2? Huh...).
Now that Nintendo has revealed the 3DS, I feel pretty cheated. I never cared about 3D, and I probably never will. Now included with my useless second screen and stylus, I get to pay premium for 3D, just to play console exclusive I know I'll want to pay. I'm hoping later on they realize "Wow, no one's buying this expensive piece of crap" and release a cheaper 2D version, but who knows, I'm willing to bet there are enough Nintendo fanboys who buy it, maybe I'll even buy it (damn you amazing launch lineup). It'll never happen but in the end, I just wish there was a Gameboy Advance 2 with dual analog sticks and a touchscreen, sporting my favorite Nintendo titles and the awesome "Gameboy" name that raised me as a child.