I stumbled across this while upgrading from gnome 1.4 to gnome 2.0 with emerge -u world (instead of emerge -u gnome) Versions 2.0 of both libgnomeprint and libgnomeprintui are not in portage, so far as I can tell.
gal2 did build successfully (it had been failing in its configure script, previously) after I finished building the remainder of gnome-2. Messed up dependency somewhere, I guess.
thanks, will fix.
uploading a gal2 revision soon which will have fixed dependencies and should do better.