Apple and Stripe are also set to commoditize the small business Point of Sale that is Square's bread and butter. iPhones were just announced to soon accept contactless payments directly, and probably also the next iPad will include the required NFC hardware.
The hardware is less important than the merchant account. The risk of charge backs means a small business accepting a credit card is effectively taking out a loan. Apple isn't going into that part of the value chain (so far).
