Nissan already has great trucks. I've had my Frontier for 8 years without a single problem and love it. My relatives also have Frontiers and no problems. My friends have Nissan Titans and again, no problems (I've driven Titans and they're nice rides).
I agree with you about the Chrysler 300. I've driven them and they're exceptional cars, better than the rest.
My understanding is that Nissan wants to discontinue making the Titan, and sell Dodge products instead.
Nissan loses lots of money on those full size trucks.