Is your DS well-liked? Do they really play together, or is your DS just a resident expert that they see when they need something?
I'd encourage empathy. Ask him how he'd feel if he asked a question of a friend and was met with the attitude.
Encourage multiple games of Pokemon at one time so that there's no line waiting to play against him.
Get him together with some intellectual peers, where he has to work to keep up a little bit.
But I'd also recognize that as long as he is not truly rude to anyone and as long as the kids want to play with him, he's probably doing okay socially. He's smart, and it sounds like it's the neighbor kids who are recognizing this rather than that he's bragging or pushing the issue. What's more, if it's not bothering them, then it probably doesn't have to worry you. I'd talk regularly with him about how to keep friendships alive, but I don't think I'd be terribly worried about the kids viewing him as an expert as long as everyone is getting along.
My mom had a saying I always pull out: "It's nice to be smart, but it's smart to be nice." I use it often enough that now DS8 says it when it applies to a situation. It seems like it might fit here.
HTH!
