The roof is now covered with Advantex (a tongue and groove covering supposed to be better than plywood) and Ice/Rain Shield. -- from their website:
Grace Ice & Water Shield offers premium leak protection for sloped roofs in climates subject to ice dams and wind-driven rain. It is applied to the roof deck prior to the application of the finished roof covering, which is most often shingles but can also be tile or metal.
With our low sloping back and weather in Maine (the way life oughta be), we covered the entire north section. We are using the same dark gray metal roofing as is now on the garage. The roofer is scheduled for next week!
I have a few pictures published in the Gallery if you are interested.