Talked to a very nice lady at American Express. Great service as always.
Anyway, she told me that Apple will occasionally do this with their accounts to verify that the card is still active. I didn't realize that, at least with American Express, that "charge" will never show up on my list of transactions. It's really just an authorization, not a transaction.
So, she said all they're checking for is to make sure that you have an iTunes account linked to that card to verify it.
So, in the end, a non-event.