There's no real easy way to say this, so I'll just come out with it. Making a third party exclusive title is both counterproductive, and a waste of money. I know that'll fall harshly on fanboy ears, but it's the honest truth. No company can survive in this fiscal climate by creating games for one platform exclusively. Ted Price, creator of Insomniac Games, knows this just as well as any, which is why today his company announced their partnership with media giant EA on a "brand new universe and franchise."
But Insomniac was not the first former exclusive company to jump ship into the multi-platform waters. Almost two years ago, Square-Enix announced that their latest entry in the Final Fantasy universe would not be a Sony exclusive. Final Fantasy XIII sold so well on the Xbox 360 that the company is now considering porting the once exclusive Versus XIII onto Microsoft's gaming darling. And about a month ago, Microsoft's cash cow Bungie Entertainment announced a partnership with Activision that would put their newest games on the Playstation 3 for the first time.
Game companies live and die by the funding they are given to develop games. A company can't remain solvent by doing just one game at a time and receiving funding from one source alone. Image that you own a company that's been funded to make a game and once that game is completed you're not yet funded for its sequel or any others. You're now faced with laying off a portion of your staff while waiting for more money to come in. Where as if you had money coming in from multiple partners, like say Sony and EA, then you can keep your staff employed and keep making games. And now that companies like Insomniac aren't under pressure to release a game quickly to turn a profit, their games will "benefit from longer development cycles, which will directly benefit you, our fans."
I can recall a day when finding out that a once exclusive game was "going to the enemy" was enough to set off a fanboy rage unlike anything the internet has ever seen. But now, hopefully, when gamers read that their favorite developers are making games for the other side, they'll realize that this translates to better quality games for them as well.