Cups will not allow printing to smb printers unless samba is already installed. There is a cups use flag for samba but not vice versa. Same goes for gimp-print and the ppds. There should be USE flags under the cups install to get those extended features.
the samba use flag makes sense, i added it to cups-1.1.21rc1. for gimp-print and ppds there is no direct connection to cups, so they don't belong there.