On early-run Wiis shipped for use in store demo kiosks, and some early consumer Wiis, the primitive "Insert Startup Disc" menu was installed. You can read more about this on the HackMii article; it's a menu that prompts for a disc, checks it, then loads/installs from it.
There are other menu prototypes shown in pre-release videos and conferences, sometimes labeled "9/14". There are several versions under this label.
Beta Materials
Inside a System Menu TPL, there exists a unused DVD icon, and an Animal Crossing message icon (shown at the September 14 press conference; see link below).
Links