The answer is timed, if you ask us. At Sony's conference, all the buzz for today's news, Free Radical's upcoming shooter Haze was announced as a PS3 exclusive title, qualified with the phrase "this financial year." It's pretty obvious what that means and we're going to squash the rumors of complete exclusivity now, so that it doesn't get out of control and used against the, er, "Sony camp". It's only on the PS3 until the end of March 2008. That's a long time, considering its release is coming in a matter of months. Oddly, a trailer has yet to be slapped onto the PS Store, but you can always check the one above.
[Update: IGN interviewed Free Radical. "Haze will only be found on PS3 this holiday season, and will remain exclusive through the first quarter of the calendar year."]