PSN Adding Subscription Service

It would appear that Sony is taking their Playstation Network in the same direction as Xbox Live in the years to come, adding a paid subscription service to the currently free system.  On the plus side it seems that the current level of service will remain free, so playing games online will still be available without charge, unlike the Xbox service.  Instead Sony will be adding 'premium content and services,' though there is no word yet on what exactly that means or how much it will cost.