Anyway, bottom line: the name totally sux (exhibits an extreme lack of originality/imagination).
This brings up a good point, but honestly, what would you suggest they should have named it?
I mean it's okay if you admit you can't come up with anything because you aren't creative enough, and I agree they could have come up with a better name, but it's way more difficult to come up with names for this kind of thing than people seem to think. There are not only difficulties with trademarking, but also issues with getting the right "marketing" angle, and getting the right brand-fit, and the right logo, and.. you get the point, it's not easy to do.
People seem to always disagree with names of things when the first come out (Retina Display, FaceTime), but over time they get used to it and don't really care anymore. The most important part of naming is to at least partially describe what it does.
With "Ping" it implies a sound (it's an onomatopoeia) which works well for music, but it also implies that you are networking with your friends since you are "Pinging" them to see what music they like/bought. There is probably more implications with the name, but you get the idea.
They clearly did some research into what would be the best name. I don't think the name is that great, but at the end of the day I don't really care. The name out of context sounds weird, but when in context, I will know people are referring to the iTunes "Ping" and not the networking term "ping."