I have lost hours of work over time using workspaces due to not remembering to press save, after having my attention pulled onto something else. Sometimes workspace tries to accommodate this with its unsaved changes prompt, sort of a 'pick up where you left off' feature, but it doesn't save everything. Just yesterday I lost about 2 hours of work.
An autosave feature saving every few minutes, or after every action, would save significant time. I'm thinking along the lines of cloud services such as Google and Microsoft documents, which cloud save constantly.
I imagine there are resource and usability implications to this, though I would happily accept a second or two of sluggishness now and again to prevent loss of work.
Where a workspace is saved with a name, the autosave would save against the named project.
Where a draft is being worked on, it could be autosaved into a drafts category.
And to throw in some idea creep, perhaps we could get version history added along with this.