Nissan already cancelled theirs. The new Toyota Tundra has not had a particularly smooth launch so far this year, and that could play into future plans for the full-size truck. There have been complaints about the quality of the interior materials, the lack of a fully boxed section frame, and basic design lapses like the bolt heads in the bed that stick up too high. It's now being reported that plans for the heavy duty version for the Tundra are now on hold inside Toyota. The HD pickup hasn't been canceled but it's not approved at this point, according to Toyota Motor Sales VP Bob Carter. Nissan has reportedly canceled its plans to create heavy duty version of the Titan earlier this year. One could speculate that the combination of high gas prices and other Tundra issues (like the camshaft matter) could cause Toyota to do the same, but Toyota has so much invested in the Tundra already (in terms of money and pride), we can easily see them addressing the aforementioned issues down the road, perhaps after a mid-cycle enhancement, and then revisiting the now-in-limbo HD version.