For a time Dells came with them. I have a Fujitsu that has a stick. Then suddenly they stopped making them. I think the patent is available to license, companies have chosen not to license it for whatever reason. It's not like there aren't patents associated with touchpads.
Both HP and Dell's current pro lines have a nub on their keyboards; and Unicomp (fka Lexmark/IBM keyboard division) sells a Model M variant with one as well. Apparently Unicomp is claiming to own the patent as well[0]
