I would say it's not that new (Argonaut, Rare, Capcom/Flagship, Amusement Vision) or that unique. Everyone contracts 3rd parties, even exclusively in some cases. Looking at all the upcoming 1st party lineups (that we know about)...
Xbox 360 Outsourced
- Alan Wake (Remedy Entertainment)
- Crackdown 2 (Ruffian Games)
- Gears of War 3 (Epic Games)
- Halo Reach (Bungie Studios)
- Ninety-Nine Nights II (feelplus)
Xbox 360 Internal
- Fable III (Lionhead Studios)
- Milo (Lionhead Studios)
PlayStation 3 Outsourced
- Heavy Rain (Quantic Dream)
- ModNation Racers (United Front Games)
- Resistance 3 (Insomniac Games)
- Twisted Metal (Eat Sleep Play)
- White Knight Chronicles (Level-5)
- White Night Chronicles II (Level-5)
PlayStation 3 Internal
- EyePet (London Studio)
- Eyedentify (London Studio?)
- God of War III (Santa Monica Studios)
- Gran Turismo 5: The Real Driving Simulator (Polyphony Digital)
- MAG Massive Action Game (Zipper Interactive)
- MLB 10: The Show (San Diego Studios)
- The Last Guardian (Japan Studio)
- Uncharted 3 (Naughty Dog Software)
Wii Outsourced
- Cosmic Walker (Gaia)
- Endless Ocean: Blue World (Arika)
- Kensax (Shift)
- Line Attack Heroes (Grezzo Games)
- PokePark: Pikachu no Daibouken (Creatures Inc.)
- Sin & Punishment: Successors of the Sky (Treasure Video Games)
- Span Smasher (Artoon)
- The Last Story (Mistwalker)
- Zangenki no Reginliev (Sandlot)
Wii Internal
- Hoshi no Kirby (HAL Laboratory?)
- Pikmin 3 (Nintendo EAD)
- Super Mario Galaxy 2 (Nintendo EAD Tokyo)
- The Legend of Zelda (Nintendo EAD)
- Wii Relax (Nintendo EAD)
- Xenoblade (Monolith Software)
Wii Collaborative
- Metroid: Other M (Nintendo SPD/Team Ninja)
Wii ???
- 100-Go de Start! Eikaiwa