There are several custom keyboard /mod/ projects with an integrated trackpoint module.
Other than that, LiteOn/Silitek SK-6000 was sold with an integrated touchpad in its palm rest in front of the numpad, and there are several similar solutions, probably the most ergonomic being a trackball in some of the Maltron 3D keyboards.
Personally, I'd rather place a rollermouse in front of a flat keyboard or place a big trackball next to one/each outer side of the keyboard, because trackpoints and similar devices cause me strain in index fingers. Note that I don't use asymmetric /full-size/ keyboards anymore, but an ergodox, kinesis advantage or a typematrix instead.