Re: Over engineered, anyone?
I know, it's a bit late.
D-Bus is a standard protocol for Linux programs to talk to each other these days.
I think the idea of it in this installer is that the installed can be controlled by a person sitting in front of the machine, either on the text console or via a GUI (two different apps providing two different UIs)... or remote controlling a VM from the hypervisor itself... or a remote VM that they've SSHed into...
... or it can be controlled by a script talking to a VM, or to physical hardware over some kind of ILO... or it can be controlled by a deployment tool that is automating it via a service of some kind, such as Uyuni or SUSE Manager... or it could be via some kind of deployment automation tool for which someone wrote a plugin: Ansible, Chef, Puppet, whatever.
The idea is that this route offers significant improvements in flexibility. Local kit, local VMs, private cloud, public cloud, PaaS, IaaS, MaaS, whatever, with a decoupled installer, you can automate deployment as you wish.
And of course AutoYast _already_ offers possibilities for self-automated deployment using config files, which can be served to client machines over almost any network protocol. I've done that myself and it's impressively easy.