(I am only half joking here)

The keyboard has an upgradable firmware and a documented microcontroller:
https://support.lenovo.com/us/en/documents/pd026745
http://www.sonix.com.tw/article-en-1002-3048

It would be great to have a keyboard with a working middle mouse button. A completely clean room firmware would allow this.

As a bonus, it would be great to implement proper negative inertia, which has disappeared from newer TrackPoint devices:
http://blogs.epfl.ch/icenet/documents/Ykt3Eext.pdf