Just a thought but I wouldn't put it past Karen Hughes to do this partly for Bush supporters like us whose anxiety level is climbing all the time.
I don't want to read anymore than that into it, but I don't know if I would be in the mood to do that if I knew Bush's numbers were not good. So maybe it is a good sign.
I think that there are two good reasons for doing this.
First, as you say, to pump up the morale of anxiety-ridden Bush loyalists (as if there are that many Bush loyalists who AREN'T anxiety-ridden at this point?).
Second, as a response to the analysis (think it was from either CNN or CBS, I remember reading it here yesterday) that the duck-hunting trip *had* helped Kerry's numbers in Ohio. In that sense this can be seen as either a complete dig at an Liberal MSM analysis the Bush team thinks is wrong ... or (assuming that the analysis is actually correct) a brilliant attempt to use humor to make those swayed see Kerry as the feckless phony that he is (use of humor can be devastatingly effective at cutting an opponant off at the knees if employed properly).