Funny thing I got the same email a few days ago relating to an old SWG account I hadnt used for over 5 years.
Sony said that those 12700 people who they believe had their credit details stolen would be contacted again.
The thing that really bothers me about this the original intrusion was weeks before the PSN shutdown they breached the system on the 16th from the reports and Sony didnt feel that there was any threat worth responding to. Then using the same techniques they assaulted the PSN database.
All the info's there on the net the Congress investigation etc.
Lets hope for Sonys sake as well as the 77million playstation users, of which I'm one, that the situation is resolved soon.
At this point, unless Sony does something monumentally stupid like continue to use the same setup that's been breached three times now, it's pretty much over except for waiting for full service to be restored. Between Sony and banks notifying customers, free and even forced card reissues, there's no good reason for any of the stolen cards to still be valid. It's actually pretty impressive how few confirmed cases there were, too. Sony claims the number is 0, banks claim otherwise but still only a few thousand globally.
Of course, if C-net is to be believed (or rather, if their source can be believed) the vulnerability is still there in other Sony networks and the same group is planning to take down additional services this weekend. If they do manage that, I'll count that as Sony doing something monumentally stupid.
So according to your link, "Expert says Sony knew of PSN security weakness". What a bunch of *******. No wonder why nothing ever works in their games, because they never bother to fix anything. I wonder why they're still in business for online games.
The reason for switching to the newer servers was because these new servers were hardened against cybernetic attacks. If you had read the news, you'd have known that. Just like how you'd know that Sony's going to be offering one year of ID theft services free.