Don't think there's recordings of CampJS for this year, but on the schedule [1] there's a talk about it listed by Marcos Caceres. You could probably ask the guy on Twitter (@marcosc).
Ahh, that completely changes the meaning. It's basically just like credit card processing in that case, but just for Android Pay (and probably Apple pay if/when they adopt the API). The transaction description/line item thing makes a lot of sense from a user perspective (granted, I am not, and do not intend on becoming, an Android Pay or Apple Pay user).
Yeah, seems to be limited to Google’s own payment services.
Just so you know, Apple doesn’t see nor store the item/s you purchase via Apple Pay, so if Apple Pay is accepted through this payment API, I think it’s unlikely to send purchase information directly to Apple.
Agreed. I'd also like to see the source for this, as I can't find it mentioned anywhere on the Chrome sites about PaymentRequest or any of the top sites talking about Chrome Payment Request.