Sony has confirmed that Resistance: Retribution for the PSP will have cross-platform functionality with Resistance 2 for the PS3. One of the features of that will be the ability to use the Dual Shock 3 controller with the game, dubbed PSP Plus!

The feature can be enabled by connecting your PSP, (complete with Resistance: Retribution turned on) to your PS3 (with Resistance 2 in the slot) using a USB lead. We'll turn you over to John Garvin, creative director over at Sony Bend Studios (developer of the game) for the details - "We remove aim assist and increase the challenge level of the game. We even support the vibration function of the controller. If you’re playing at home and want to experience Resistance: Retribution in an all new way, this is it."

Furthermore, players will be able to activate 'Infected mode'. Back to John for more detail - "Infected mode provides an alternate story within our alternate history. While in prison for desertion, Grayson is recruited by Specter Lieutenant David LaSalle (from the R2 storyline) and is infected with a mutated version of the Chimeran virus … a different version of the virus that infects Nathan Hale.

"While playing in 'infected' mode, Grayson wears a Specter uniform and has glowing Chimeran eyes. He gets to use one of the new weapons from R2: the HE .44 Magnum, which fires explosive rounds that can be triggered remotely. He has regenerative health and no longer needs to look for health packs. He can breathe underwater, allowing him to reach hidden areas that he could not reach before. And we’ve added another whole class of Intel that are hidden throughout the levels. Collecting all of the “infected” intel will unlock another R2 weapon, the Plasma Grenades."

A cynic might argue that rather than providing you with an extra feature if you have both games, Sony is denying you content if you just have the PSP version. SPOnG would hate, of course, to be that cynical...

^{Source: PlayStation Blog}