What is keylink good for? It is simple: I think that having Ctrl-Alt-Del as special case is ugly. It would be probably acceptable if there was just one such exception, but there are two of them. (Second is spawn-console, normally mapped to Alt-Up and normally unused).
On the other hand, if you want to cut-and-paste from console to console, you are expected to use mouse. Not every computer has mouse, and even if mouse is available, it is braindamaged to have to press button on mouse for paste.
So I decided to take prev. system, and to remove some limits. With keylink, there are 255 events which can be sent to userland. Events can be read from /dev/keylink. I currently use keylink for mouse emulation (even on machines with real mouse - it is annoying if you have to search for mouse just because of paste). Other uses could include "log me in on next console" key, Ctrl-Alt-End power-down key (it is handy to have reboot and powerdown separated), go suspend, go hibernation keys, ...
Patches are ready relative to 2.1.90 (they should apply pretty cleanly even to 2.1.128).
Keylinkd, which emulates mouse-systems mouse on /dev/keymouse is available here.