Imagine you would like to install Debian on a Server/Router/Firwall... short on a machine which should run without a monitor and keyboard. And maybe you own only laptops - how could DebianInstaller help to install Debian on that machine?
IMHO the DebianInstaller should be able to run remote (on demand) with ssh via Ethernet, Wlan, RS232, IrDA, USB, BT, LPT, Modem, ISDN, packetradio, GSM, GPRS, ..... short on any network connection the installer recognizes.
Before accepting incoming connections, a firewall should be started.
A BlackBoxInstall-O-Mat script should support to make an individual DebianBlackBoxInstaller so that it would run on a FD, USB-Stick, Zip-drive, CD-ROM or even with PXE.
Similar to this topic is an option to fetch an image for PC manufacturers to install once, making a partition copy and than clone this partition onto identical hardware.