For an interesting take on this, see Ghost in the Shell: Stand Alone Complex. Many of the cyborgs and secretary-bots have expandable spider fingers that type at lightning speed. People without augmentation can still use the keyboards, so it's device and space efficient and keyboards are dirt cheap and the keys can take a lot of pounding.
QWERTY is a more stable protocol. You'd have to do less rip and replace of hardware (read: body parts). You could even handle Dvorak with only a software upgrade ;-)
