I was just talking to a guy who says it's rumored that there will be a 500 hp Tundra. Has anyone else heard about this?

that rumor is FALSE. although, the new tundra has a high towing capacity.

The rumour is TRUE. the new 5.7 L will have HP close to 400 hp. TRD has a super charger designed already. It should have CLOSE TO 500 hp with the SC.

sorry, that's too much of a reach for me.
that's like saying that there's a 400hp camry.
200hp corolla...

if you're talking about hp after adding aftermarket parts, then yes, it's possible...then again, what isn't possible?