And looking at the list, there are some pretty nice features excluded. For example network support, or editing compressed or tar files. I guess the expectation is that these can still be accomplished by leveraging commands outside the editor. This is a clean approach.
Okay, but no diff mode? vimdiff is fantastic! And I'm not sure how you recover that functionality without multiple workspaces. Maybe the answer is you don't. Use vis for normal editing and pull out vimdiff only when you need it.