Wow. This is going to take a while to process, but it seems like they've moved away from the concept of how SharePoint workflows function, which involves a list of data that has a workflow attached, to a new concept where the workflow has its own list via the common data model. So, create a workflow, and then optionally create a list/table to store data that is needed as part of the workflow. Obvious questions abound: where is that list stored? Do we have access to it outside of the workflow? Can we report on current values in that list? How is security handled? How much data can the service handle? Is the data available to multiple workflows?
But unfortunately, it looks like there is still no support for state machine. The docs have an example of an "approval loop", and perhaps it's just early, but reading through it I couldn't readily identify the benefit of the loop in the example workflow.
Though the data gateway sounds good, though unfortunately the docs haven't been updated to cover it.
