Apple now claims that being a services company is important to them. If they’re able to address the latency and reliability issues that their services have historically been plagued with, they may have succeeded at exactly what they set out to improve. But I still personally won’t consider them a good services company until they take tangible steps towards making their APIs far more open than they have been to date. These types of companies understand that they alone cannot build all of the interactions their users would find useful (nor would targeted, limited partnerships suffice). They earn the adoration of their developer community by empowering them to create the next big app or feature, standing on the shoulders of giants rather than sitting in their pocket.
I completely agree with Bryan. iOS devices have become more powerful and capable in recent years as Apple has opened up the platform with extension support, custom keyboards, widgets, new developer APIs and more. In that same way, Apple's services from Apple Music to Apple's Notes app, could be improved through new APIs that go beyond client-side features. Imagine being able to connect something like IFTTT to Notes.app and creating a recipe to automatically append any links you favorite in Pocket to a note in Notes.app.
I think it will happen, but it could be a long wait. We've seen through the introduction of various extension points in iOS that Apple is extremely cautious about relinquishing control. It just won't happen overnight, it'll be a gradual expansion in carefully considered and controlled stages. As Bryan points out, CloudKit web services (which can be openly communicated with over HTTP) may be an early reason for optimism.
Closed systems have enabled Apple (and members of their developer programs) to deliver many of the user experiences we know and love, but past performance does not equal future success. While embracing interoperability might require a philosophical shift away from what has worked to date, I worry that the alternative is Apple continuing to stretch themselves thinner and thinner as software continues to eat the world and hardware continues to become smaller, cheaper, and more ubiquitous.