Currently there are only a few things that can be configured in the Docker Engine and Swarm. This will enable more operations such as Engine labels and Swarm strategies.
Machine currently supports running Boot2Docker for "local" providers and Ubuntu for "remote" providers. This will expand the provisioning capabilities to include other base operating systems such as RedHat like distributions and possibly other "just enough" operating systems.
Currently, the Machine on Windows experience is not as good as the Mac / Linux. There is no "recommended" path to use Machine and there are several inconsistencies on Windows such as logging and output formatting.