It's definitely rude to repeatedly state that anyone who's opinion is different from yours is "adding FUD" and doesn't belong in the thread. 

Stephen, and Steven, and Paul, and I all perfectly well understand what "evaluated at function call time" means.

It's a way to spell `if arg is sentinel: arg = ...` using slightly fewer characters, and moving an expression from the body to the signature.

I won't stoop to saying that advocating what you do is FUD. I can even understand why someone would want that in Python.

I'm still -1 because I don't think the purpose alone is close to worth the cost of new syntax... And especially not using sigils that are confusing to read in code.

The topic of "late binding in function signatures"  simply isn't *orthogonal* to "late binding in the general sense." Yes, they are distinct, but very closely adjacent.