I'd say your Hybrid thought
I'd say your Hybrid thought is pretty unlikely considering most everyone has canceled hybrid models in pickups over the last few years (GM had a model they have since discontinued). The problem? Price/benefit with less torque and HP - those are big items for trucks.
A turbocharged and/or diesel engine is more likely.
Now, if they could fix the driveline vibration issue, then everyone would be happy. Toyota would also spend less time dealing with lemon law hearings.