How did this trade get dug up? Now I feel compelled to comment.
Carolina didn't get much out of it -- just a couple of trade chips -- but Staal was on an expiring contract and Carolina was in a rebuild so they weren't going to re-sign him. He had been in decline for a couple of years (this was before he revived his career in Minnesota) so they weren't going to get a first-round pick for him. Two seconds and a prospect was a pretty good haul.
It was a great trade for CAR at the time b/c Staal was having a meh season and was terrible with NYR. Sadly, Martin was a bust; Saarela's attitude problems ruined him; and Kayumov may never come over.