Sony Bend the studio responsible for the upcoming title Resistance: Retribution seems the be the only studio who has a hold on the technology of using a Sixaxis. Developing PSP Plus to be able to use your existing Sixaxis controller and sync it with your PSP via Resistance 2 makes them one of a kind in the Sony game studios.

Sony said they weren’t sure yet if the tech would be passed on to other studios let alone having considering it.

We have a hunch Sony will look how the reception is with the game and how PSP Plus will affect gamers. And it’s success depends mostly on the place people will play it. At home or on the road.

Source

Both Resistance Retribution and Resistance 2 will be able to connect and interact between eachother. 

To do this, you’ll need to connect your PSP to the PS3, via USB. Once you have them connected, go to the Resistance 2 options and select “Infect your PSP” What is infect your PSP you say? Well read below to find out what it is. 

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.

Not only that but they have also announced a new feature called PSP Plus+. PSP Plus+ is a new feature where you’ll be able to connect your PSP to your TV (Limited to PSP 2000, and PSP 3000 models). Then you’ll be able to use your DUALSHOCK 3 to play your PSP games.

Source