As I speculated yesterday, Apple's lawsuit was most likely over the
rumored Asteroid audio interface. Apple has subpoenaed AppleInsider,
PowerPage, and Think Secret to try to determine the source of the leak,
It's not clear from Engadget's tip whether Apple is seeking a subpoena
or has gotten one already. Since a subpoena is a court order, parties
would legally have to appear in court, though legally journalists don't
have to divulge stories.
Anything you read here is entirely speculative, and I'm certainly not
qualified to comment on legal issues! I will say companies do have some
good reasons for trying to keep their secrets: competitive
manufacturers can get a real edge, and product leaks can create user
expectations companies don't want. In any case, for better or worse,
for many of us it's more important to maintain our relationships with
these companies because our primary job is writing about released
products. (Oh, and that Apple flying car — that's not happening.
Though I hope Apple sends me a review model if it does.)