Following a password change and agreeing to the latest user agreement, the player online portion of the PSN will reactivate.
Of course before that you will have to download the latest update firmware 3.61 onto your PS3 before you can do the above mentioned. But once you do, you can enjoy the online feature of the PS3 again that enables playing with others.
Below are some of the instructions you’ll need to follow before playing with your friends again.
If using a PS3, your password can only be changed on your own PS3 (or a PS3 on which your PSN account was activated), as an added layer of security. If you have never downloaded any content using your account on the system, an email will be sent to the registered sign-in ID (email address) associated with your account when you first attempt to sign-in to PSN. This e-mail will contain a link that will enable you to change your password. In this email, click on the link and follow the instructions to change your password. Once you have changed your password you can sign-in to your account using your new password.
We strongly recommend that all PSN account holders with PS3s update their systems to prepare for when PlayStation Network is back online. The release of this update is a critical step as we work to make PlayStation Network significantly more secure. Thank you for your continued support and patience.
More details can be found at the US PS Blog.
Source: US PS Blog