The '15 F150 will NOT be unibody, it will still be body on frame. There will quite likely be lots of aluminum in the truck, reducing weight drastically (700 lbs is the target). There will be another EcoBoost engine displacing 2.7L (V6) and putting out 300+ HP, while getting outstanding fuel economy. I also look for the 6.2L to go away. Look for the 3.5L EcoBoost numbers to go up across the board (HP/torque/MPG).
This is going to be one bad-***** truck, and the others will have lots of catching up to do. Heck, according to the latest pickuptrucks.com half-ton shootout, they have a lot of catching up to do to meet the standards of the CURRENT F150!