Technically, MSI has supported GUI-less command line installation from the beginning, with relatively good dependency management and error reporting. I've invoked MSIexec from install/provisioning scripts fairly often as part of continuous integration toolchains and it works great. Some of my applications also know how to pull down dependencies (like the windows SDK, or the MS CLR) off microsoft's servers via HTTPS and then invoke the installer automatically so features that depend on them can Just Work.

If the package manager knows how to leverage this (no doubt it will), that will allow GUI-less installation of a huge percentage of windows apps (MSI is relatively popular now despite its quirks.)