What he is apparently doing is canvassing the idea with operators. "If you had a keyboard version, how many would you take?"
And he has taken this beyond just chatting: actual prototypes - not just mockups - have been sent to senior executives at some operators. I'm not allowed to even hint which operators... but I can report that the keyboard has "issues" which are not yet resolved.
The Register indicates that the keyboard iPhone will not be unveiled this year. Aimed specifically at corporate buyers it would see a release around this time next year. They stress that while it is not guaranteed that it will reach the public it does in fact already exist!