And it is in GSD as well. Do you mean you can't switch your console
layout using "loadkeys colemak"? If so, then the problem is that the
upstream names this layout "en-latin9", so as a "workaround" you can try
"loadkeys en-latin9".
I don't know what is the policy of the other distros, but for example
"Arch Linux" just renames "en-latin9" into "colemak"
(https://projects.archlinux.org/svntogit/packages.git/tree/trunk/PKGBUILD?h=packages/kbd).
Perhaps it would be better for us to modify a recipe for "kbd" package
to make a symlink "…/share/keymaps/i386/colemak/colemak.map.gz" that
would point to "en-latin9.map.gz". What do people think?
Or do you mean anything else when you say that Colemak feature is missing?
P.S. I use dvorak :-)