Note that there's some improvements in the multi-workspace experience in 8.3 - besides some improvements to the way the API works, you're also able to provide unique icons per tab in the TabbedResourceWorkspace (on your individual ResourceEditors) - since we're now using the same technique more ourselves with the changes to the way gateway/client/session event scripts are managed.
I already have this per resource type. Do you mean per individual resource?
Is new to 8.3.0, allowing the actual tabs at the bottom of a particular workspace to be disambiguated by icon (in the generic TabbedResourceWorkspace). If you're using a custom workspace then you could of course have always done this.
Ah, yes. I implemented ResourceWorkspace.