bp888, getting to the Wing is not a problem if you have a same-day boarding pass. If you want to exit the airport after using the Wing then there's a problem. You cannot exit from the Departures floor and if you go through the security area near the escalator they will not let you back into the arrivals area.

pegasus8228, thanks for the links. Where does the lift open out to on the Arrivals floor? Is it near the security checkpoint or somewhere where I can be quite sure of being able to exit safely?