This is a good move for sony, if they could bring the games to the gamers sofa impulse buying will kick in plus the ease to get games on a rainy day will be great.
Also a think sony should start making our psn accounts global accounts for sony products to keep a history of our purchases and tastes. This global account could move with the user as he keeps growing old that way if he wants to play old titles via backward compatibility he can get those titles.
This is the obvious direction for the big corporations like microsoft, sony and apple. Steam has done a great job and so the apple store too, proven methods like these should definetly start becoming a standard in todays market where digital distribution is a reality. Movies, Games, Shows, Apps at a discount price or better priced than retail will be the market of tomorrow because everyone can have a store at home.