Sony announced this week that PlayStation Now will be available as a subscription-based service on PlayStation 3 consoles starting Tuesday, May 12th. The streaming service offers over 100 games such as Batman Arkham City, Bioshock Infinite, Mass Effect 2, and Saints Row IV for $19.99 per month.
PlayStation Now also offers streaming games to rent individually. That part of the PS Now service has been available on PS3 since launch. New titles available this month include Fat Princess, F1 2014, Sanctum 2, Dynasty Warriors: Strikeforce, and Farming Simulator.
PlayStation Now titles are playable on PS4 and PS3, PSVita, and PlayStation TV, as well as select Sony Blu-ray Disc players and TVs (select Samsung TVs will also soon support PS Now). Sony says the service will be available on more devices in the future.
Sony offers a free 7-day trial of the PlayStation Now service. You can see a full list of games available at this PlayStation community post.
Source: PlayStation Blog