Existing association may not matter, though. Consider that iTunes began as an MP3 player app. Full stop. That's all it was. At some point they added support for loading your songs onto portable MP3 players, but I don't remember if that was in 1.0 (this was pre-iPod).

Then they added a store, which wasn't a huge leap, but there's a difference between listening to music and shopping for music, even though one can drive the other.

Then they added movie and TV purchases. Not a huge leap from buying music, but nothing at all to do with managing your MP3s.

Then they added syncing your iPhone, which has a multitude of features entirely unrelated anything anyone did in iTunes before. But, hey, you need to sync your music, too.

THEN, App syncing and purchase.

I'm sure I'm missing a feature or two in the chronology, but you get the point.

iTunes has a rich history of having seemingly unrelated shit jammed into it. Sometimes there are alternatives for what iTunes can offer (Netflix Watch Instantly, Amazon MP3 Store) and sometimes you're locked in (iOS device sync).

But either way, Apple seems to get away with it. The trojan horsiness of iTunes gives them leverage to accomplish things that would be much, much harder for other companies.

We'll see if that holds for Ping. I wouldn't bet against it, even if I wouldn't put much money on outrageous success, either.

Hopefully iTunes 10 will at least be more performant. All this cruft has come with a cost.