Pokemon Diamond for DS

I resisted buying a handheld game system for my son for many years. I see too many small children walking around with their DS, Gameboy, PSP, etc, bumping into walls, totally oblivious to the world around them. I feel children should experience the real world before they become entranced by a virtual world, like that of Pokemon.
Then, my son received a Nintendo DS for his birthday, from a relative, who had not asked my permission before purchasing it. I admit it, I couldn't say no to my child. He was already 8, so I went along with it. He played a few different games, and then he discovered his cousin's Pokemon Games. That was it! Since then, the entire household is involved in all things Pokemon. My son has to have every Pokemon game that has come out, and there are a lot of them!
The latest one he asked for was the Diamond. I've played it myself, but, to be honest, it does not thrill me. My son, however, is incredibly excited by every Pokemon he meets in this virtual world! He loves getting the names, and different skills and qualities of each one. I can't believe it, but he has 493 Pokemon characters memorized! Is this a bad thing? I don't think so, since if nothing else, it is sharpening his memory skills, and his ability to pay attention to details.
When he's playing the game, I find the sound is not too annoying. And, he will share with me what is going on in his game, so he is not completely locked into his virtual environment. He gets very excited when it's time to battle the gym leaders, and somehow, he always wins.
I think the Pokemon games are fairly harmless fun for kids of school age.