Yes, he should end it. I'm sure he's in shock, and since public speaking isn't his strong suit, he should stop trying to reach out to the press, most of whom hate him and would be ecstatic if he dropped dead.
I'm sure I'll get called a troll for this, but this presser, and Rumsfeld's resignation are the blood on the stone; this presser is what Bush needs to do if he's going to achieve any further success in Iraq. I feel the man's pain - he's thinking about our troops in the Iraq theatre and the WOT and doing what he has to do as a politician to ensure we get as far along in those matters are possible while he's still President. It's sad but necessary.
I think, in retrospect obviously, he SHOULD have let Rumsfeld go before the election. Perhaps it would have been the "sacrifice" the moderates needed to vote our way.