"network features" are accessible only with PlayStation Store.
Sony appears to have adopted an online pass system similar to EA's meaning Resistance 3 could be the first of many. Sony is yet to offer any comment.
This isn't entirely new as both ModNation Racers and PSP's SOCOM: U.S. Navy SEALs Fireteam Bravo 3 both came with an online pass like system. The 'PSN Pass' stickeron a 320GB PS3 bundle with Resistance 3 headlining the box.
The online pass requires activation before a game can access online components while second-hand owners need to purchase the one-time codes to get multiplayer. This is all fine except when digital stores start playing up and codes won't activate.
Resistance 3 releases exclusively on PS3 this September.