Update:
Now ipxe supports loading pxe scripts with menus and everything, so nothing would need to be hardcoded in the live CD. It would just do
kernel http://path/to/boot-script.ipxe
And the boot-script would be updated with new releases and everything.
Additionally, ipxe.efi could also be included in the live CD, so that it does the same thing in newer UEFI-based computers.
Update: path/to/ boot-script. ipxe
Now ipxe supports loading pxe scripts with menus and everything, so nothing would need to be hardcoded in the live CD. It would just do
kernel http://
And the boot-script would be updated with new releases and everything.
Additionally, ipxe.efi could also be included in the live CD, so that it does the same thing in newer UEFI-based computers.