I don't know if you all already know this or not, but just in case you don't, GameStop now sells PSN content in stores and online. That should be good news for those who don't believe GameStop to be the Devil incarnate.
I assume the content sold in stores will be mainly PS3 content such as DLC and popular PSN titles. But as the link shows, you can buy codes for minis, PSP titles, and PSone Classics online.