I haven't heard of any immediate plans to do it in WDW (though it's part of the longterm plan), but from my understanding they'll use a similar program in Shanghai from the park's launch. I'm not techy enough to understand exactly how it works, but it will use similar tap-to-use technology like Apple Pay. I assume that using it will be quite similar to the WDW's current Magic Band system, just with something different that gets tapped. I do wonder about the technological problems they'll have getting everything to work. From a maintenance perspective, there's a huge advantage to having all guests use identical devices provided by Disney
Given even further reliance on cell phones, I hope they have lots of charging stations there. I hope it works out well and comes to WDW. Though I don't mind Magic Bands (I actually like them), others in party would much prefer to use their cell phones.
