Okay, after about 15 minutes getting transfered to and fro, I got a straight answer from Isuzu America. This is the bottom line:

First Owner:
36 months, 50k miles (bumper-to-bumper)
120 months, 100k miles (powertrain)

Subsequent Owners: (family members retain full above warranty)
36 months, 50k miles (bumper-to-bumper)
60 months, 60k miles (powertrain)

I'm happy with this, that means that my new truck will still have about 18 months left on the bumper to bumper. (Did I say my new truck? Why yes I did! Details to follow...)