@Balance: Your proposal seems like a fairly fundamental shift in language semantics. It reminds me of the discussion here about introducing new language constructs for immutability. (It also raises the idea of using :=). It might be worth reading through that to see what some of the designers of Julia have to say about that.
I am mostly a spectator, but I suspect such a change is unlikely to be considered by the core devs, in part because (IIUC) it would break so much existing code.