I think it is just a convoluted way of getting people to just buy everything from the PSN. Because really, why bother going through a stupid registering process if it really just makes you pay the price of a PS3 game. I think it would be easier (and make slightly more sense) to just make the price of digital PSP games cheaper. With the popularity of buying used games these days.
I can understand not simply letting you rip the game 100% free. But in all honesty, if I could even do a download/rip of my PSP games (or PS3) for like $1-$5. I would be 90% okay with not using a CFW on my units. I still would like to have the physical discs though.
The most immediate problem I can think of for any of the digital stuff is times when the PSN/your network is down. Since without signing-in will normally lead to the games not working.