To show that the Sony's 1st party firepower comment has merit, I borrowed this from another thread.
Nintendo:
just one big Nintendo studio
Internal Sony's Studios:
Sony Computer Entertainment Inc.
Clap Hanz – Everybody's Golf series
Polyphony Digital – Gran Turismo series
SCE Japan Studio (Project Siren Team, etc.) – Ape Escape series, LocoRoco
Team ICO – ICO, Shadow of the Colossus
SCEI Subsidiary Divisions
Sony Computer Entertainment America Inc.
Incognito Entertainment – Twisted Metal series, Warhawk
Naughty Dog – Jak & Daxter series, Uncharted: Drake's Fortune
SCE Bend Studio (formerly Eidetic) – Syphon Filter series
SCE Foster City Studio – Jet Li: Rise to Honor
SCE San Diego Studio – NBA series, MLB: The Show series
SCE Santa Monica Studio – God of War series
Sony Online Entertainment LLC. – EverQuest, Star Wars Galaxies
Zipper Interactive – SOCOM: U.S. Navy SEALs series, Massive Action Game
Sony Computer Entertainment Europe Ltd.
Bigbig Studios – Pursuit Force
Evolution Studios – World Rally Championship series, MotorStorm
Guerrilla Games – Killzone series
SCE London Studio (includes Team SOHO & Camden) – The Getaway series, SingStar series
SCE Studio Cambridge (formerly Millennium Interactive) – MediEvil series
SCE Studio Liverpool (formerly Psygnosis) – Wipeout series, F1 series
Sony Computer Entertainment Korea Inc.
SCE Korea – EyeToy: EduKids, GloRace: Phantastic Carnival
Microsoft Internal Studios:
ACES Game Studio: Flight Simulator series, Combat Flight Simulator series and the upcoming Train Simulator 2
Lionhead: Black & White series, The Movies, Fable series
Rare: Perfect Dark series, Kameo, Conker series, Banjo series, Viva Piñata
Turn 10: Forza Motorsport series
Wingnut Interactive: A new studio set up in conjunction with Peter Jackson (they will be producing alongside with Bungie Studios a new game based in the Halo universe)
Xbox Live Productions: A new first-party studio set up to develop Xbox Live Arcade games and digital video content