Images tossed into a Pages document, what resolution are they printed at? Does Pages keep the resolution the same for all image files' originating resolution? Or do printers automatically down-rez the image to 150 ppi or something?
The resolution is whatever it was originally plus whatever you rescaled it to.
However when you print or export to pdf all objects which are effected by transparency will be reduced to 72dpi bitmaps by OSX's colorsync filters.