Ah, whoops. I should have looked closer at your examples @Clemdz - I had thought that when you did obj.{ a, b } = anotherObj, that obj was just getting bound to anotherObj, not that it was getting restructured. (meaning, I thought it was literally just a different syntax for the as proposal) I see more similarity now with the restructuring syntax I was proposing in the object-restructuring thread.
I think @senocular has a good point though, where I'm not sure how valuable it would be to restructure and destructure the object at the same time, and maybe it would be good to treat this more like an alternative syntax for the "as" proposal.