Anesthesiology on board
My group(a group of anesthesiologist in the NE USA) are already looking at software to streamline billing, QA, and anesthesia records using a "tablet" computer of some sort... Electronic record keeping is the future of medicine, and it wouldn't surprise if the ipad was somehow involved.
Many hospitals already ARE making heavy use of PDAs / Smartphones integrated into their services.
You find the next nurse or person you talk to as you go down the hall already has the information in their hands that you gave to the people in the last room.
IPads have a lot of potential in medical use.
The biggest hurdle will be a convenient protective Flip-cover and shoulderstrap type of carrier.
The advantages that the PDA/Phone devices have, is that they can be instantly stuffed in the pockets of your scrubs, totally out of the way of things you need to be doing.
Their disadvantage is the tiny screen.