Premium fuel required?
Might not matter to a Lexus (or Landcruiser) owner, but for a pickup (average) owner it's usually a bad idea (for example except for the Ram Hemi no other pickups have that requirement).
I think its a bad idea. Toyota's money would be better spent on a bigger more competitive V-8 for its next gen Tundra, Sequoia, Landcruiser than trying to squeeze out a few more ponies from the 4.7.