Sony have announced that this weekend that everyone who owns a Playstation 4, regardless of if you have Playstation Plus, will be able to access online multiplayer this weekend.
Starting on Friday February 13 at 6am GMT and ending at 6am on Monday 16th February, you will be able to play all your games online for free. The Playstation 3 will remain the same as you do not have to have a Playstation Plus membership to play online.