No price or details were mentioned, but PlayStation's Kaz Hirai says that a "premium level" subscription will come to the now free PlayStation Network some time in 2010. And by subscription, he means NOT free.
What you will get is a kind of "service offering with premium content and services" that you can't get in the free edition, but what that is is unclear. But it's unlikely that Sony will charge for the services they give away now, such as the ability to play for free online. [Gamespot via Engadget]