With over 70 million user accounts compromised in the "illegal and unauthorized intrusion" of PSN, this is serious. Sophos's Graham Cluley explains that hackers potentially have access to your other online accounts, have a verified email address where they can directly contact you, and, of course, your PlayStation Network.
You're right to be worried with Sony explaining that the following information-- as well as your credit card data -- may have been compromised:
name, address (city, state, zip), country, email address, birthdate, PlayStation Network/Qriocity password and login, and handle/PSN online ID. It is also possible that your profile data, including purchase history and billing address (city, state, zip), and your PlayStation Network/Qriocity password security answers
Act now: follow these tips to limit the harm to your other online accounts, credit cards and identity.