Superman 662 (May 2007) advances two separate storylines, by Busiek, Pacheco and Merino.
Picking up on the Auctioneer storyline from Action Comics, Superman tries to figure out who the other Kryptonian on Earth is, which the Auctioneer refers to. He checks out Power Girl, but even though she is Kryptonian, being from another universe means she registers as something other, and cannot be the one the Auctioneer was talking about.
Superman visits Zatanna, to get some background on Arion. Zatanna fills him (and the reader) in on the character’s background as leader of Atlantis, and his actions since. She also references his most recent appearances, during Day of Vengeance, events which do not correlate with Arion only recently arriving in this period. But that is not a mistake, rather a set-up for a later issue.
Aside from that, Superman just spends most of the issue pondering whether Arion was right in his forecast of the future.