Sony has detected "irregular activity" on their network and, as a precaution, have initiated password resets for several of their customers. Of course the great PlayStation hack is still fresh in our memory. Beyond the potential reference jokes, this time could be a sign that they learned their lesson.
My hands are still in head-crushing formation.
My gut feeling is that Sony has noticed odd traffic from attackers trying to use break into accounts using information compromised from other sources (such as the recent Adobe hack). I actually received a similar email from Blizzard, just a couple of weeks after the Adobe hack, urging me to reset my password. It does not surprise me that whoever has access to the blob (heck it is probably public by now) would be poking gaming services to extort or troll.
I will give Sony the benefit of the doubt (especially considering how probable it is) and say they have learned from their lesson. This is the same practice used by to good security firms: push the big red reset button whenever something looks fishy and keeps your affected customers informed.
Of course I could eat my words if it is found out that Sony knows of a gigantic problem behind the scenes — but I doubt it. Congratulations on handling the situation properly, Sony, even if it does open you up to misinformed trolls.