It is currently possible to implement a workflow process for publishing content by having a private section of the site where content is authored and then publishing to public pages (or scheduling for publishing) can be done by those with permission to edit public pages using the Content Manager. So in essence mojoportal has features that allow you to establish a content authoring, approval, and publishing process based on roles. I've talked about this approach here before. I think the problem is that this approach requires the site owner to understand a lot about what is possible with mojoPortal to come up with their own workflow.
I do think it would be better if we had a more automatic easy to use way of implementing workflow. I've been contemplating having options to attach a workflow to content so that its more obvious how to do workflow, what stage the content is in, what the next required step for publishing is (ie approval).
I'm still kind of thinking it through so any input on what this should look like when its implemented would be welcome.