I love Apple and all but they'd have to somehow make it easier then Venmo, because it would be pretty hard to convince my non-tech friends AGAIN to move away from something that works so well
This service will push adoption of apple pay as well as benefit as people start to use it; I predict it'll take off here in exactly the same way that Paypass and similar took off in Australia when they were introduced. Lots of skepticism tied to a huge acceleration in uptake.
I will say that Venmo already is installed, is aware of my contacts, who I pay the most, and my payment details. But I use Apple Pay and I agree that it would be heavily adopted just because it's already there and it's one less "account" people have to worry about.