i picked up 2 trackmaster sets, wild, whirling ol weezy and crankys spinning cargo drop.
i got the cranky set first, as it has the working hard diesel variant. when i paid, it scanned up cheaper than stickered [$55 instead of $70] so i went back and got the weezy set too, which comes with "transition thomas". thomas has chassis holes ready for the new wheel arrangement used on the sleepered track.
click on diesels pic to visit the fisher-price engines page, and thomas to go to the boxed sets page, for more photos of both sets and characters.