Yeah that's only Python 3, which most people aren't using yet. Also it's not optional typing -- it's optional annotations. Someone would still have to actually implement the type checking -- not even sure that's been done.

I have wanted to play around with implementing some type checking, but none of my stuff is Python 3 unfortunately.

I read that and it gave me 5 seconds of hope. But then

"The only way that annotations take on meaning is when they are interpreted by third-party libraries"

and

"Following from point 2, this PEP makes no attempt to introduce any kind of standard semantics, even for the built-in types. This work will be left to third-party libraries"

means the author really isn't serious about it. If you don't have a standard semantic you've got nothing useful.