Why are you trying to convince them? Do you think Nintendo is desperate for their sales dollars? If 3DS sales anything like DS (which according to your friend's thinking it will) then I'm sure Nintendo won't miss them. The best way to prove them wrong is to get the 3DS yourself and enjoy the hell out of it. If they still too much of a Sony snob to care, so what? Sony needs sales too (more than Nintendo too).
However as for the comments:
"PSP looks much better [graphically] than 3DS" - Ah... no. Look again. Plus PSP isn't in 3D. "3DS is for casuals; like the DS" - So? there were tons of great games on DS. "Pilotwings is a minigame" - Yeah, I agree. It's basically 1/8 of WSR maybe tripled in size to be 1/3 of a full game purchase. As much as I'd love to play it, I couldn't justify full price unless there's more places than Wuhu Island (which I've explored every inch of) "The 3DS line-up is almost completely made up of remakes" - Exaggerated but true. It's called a launch line-up. "Steel Diver is a tech demo, and a bad one at that" - Have they played it? No. Could be a ton of fun. "3D is a gimmick, and will fail like 3DTV" - Yet 3D is becoming the norm. 75% of Sony's TV line are 3D.
