I was just reading about this in diesel tech magazine.
Here are a few more details, the 4.4L is slated to be an option in the F150 as early as 2009, and they claim this motor puts out 325 hp & 520 ft. lb. of torque.
Scheduled to be released in late 2009 is GM's 4.5L Duramax for their 1/2 ton trucks & H2
No actual press release yet, but Dodge has been rumored to be gearing up to release their 1/2 ton Cummins shortly after the Ford / Chevy introductions