Hello -- I am one of the key people in the TypeMatrix company and just want to formally tell Colemak users that our current keyboard supports the US English version of the Colemak layout.  It is an internal switch in our keyboard (FN+F5) and we provide skins labeled with the Colemak layout that fit nicely over the keyboard to support this layout.  We have both clear and black skins, although I must say that we are running out of the black version but will be reordering at some point.  I hope that users will check out our keyboards as the design of the TypeMatrix also lends to more ergonomic typing postures and practices.  Some customers have requested a tutor to go along with the TypeMatrix design -- anybody interested???
Mary @ TMx