The PlayStation Now streaming service is set to expand very soon. Currently the service allows you to stream PS3 games (for a monthly fee) from a library that now includes 483 titles. Sony has announced that the service will soon allow members to select and stream PS4 games.
Current/active PS Now subscribers will be selected to participate in an upcoming beta to test out the new titles. As of yet there are no exact details as to which PS4 games will be available to stream but it was announced that PS4 games will be a part of the current subscription service when they are made available.