So anyone can add

Pay to their phone, even Android or Windows phones... Don't think so.
That's what I mean by an open standard. Sure NFC tech might be open but Apple didn't just announce that, what they announced will only ever work with closed Apple hardware, it has even got Apple in the name.
The sole purpose of the system is to make more money for Apple, by forcing people to buy their devices if they want to use it, and by charging the banks for the privilege of actually using it.
Really contactless payments should conform to exactly the same standards and protocols no matter what hardware it is running on. Sadly it doesn't look like that will happen now.