Oceancrosser,
Yes, the A320's etc have a Ram air turbine connected to one of three hydraulic systems. There are 2 engine driven systems (1 each side) plus an electric centre system which has a ram air turbine (RAT) attached as a backup. The RAT can also work as an electric generator if your other electrics are broken, provide the centre hydraulics are O.K. With the APU, it does have requirements with respect to cold soaking. In the company I work for it is quite common to have maintenance requirements to do in flight starts of the APU for quality assurance. This requires the APU to be started after 2 hrs of cruise flight and the results noted. Also my company only has 120 minutes ETOPs.
Other stuff for ETOPs include fire suppresion and maintenance and component tracking for ETOPs critical parts.