iCloud gets new storage options - 5GB free, 20GB for 99c per month and 200GB for $3.99 per month - and new, simpler photo editing tools, and it also gets what looks rather like a Dropbox-style file system that enables you to share data between apps.
Edits are saved back to iCloud drive so they're available on your Mac, other iOS devices or Windows PC.
If this is as good as it looks, it's going to be amazing. With Continuity, your iOS devices and Macs know where they are and what you're doing, and you can hand over from one to another - so you can start writing an email on your iPhone and finish it on your Mac, or view a web page you've been looking at on Mac Safari and see it on your iPad.
In a really nice touch you can use your Mac as a speakerphone for your iPhone, even if your iPhone is in a different room charging.
We've seen predictive typing on other platforms, of course, but Apple's version is context aware - so if you're replying to a message suggesting dinner or a movie, your typing suggestions will include "dinner" and "movie", and if you're replying to a tedious work message the available suggestions will use tedious work terms. iOS 8 will also, at last, support third party keyboards.
More efficient Mail
iOS Mail gets a few new gestures that make processing mail easier: you can swipe to mark messages as unread, swipe a bit more to flag them or swipe further still to delete them.
There's also an interesting solution to the problem of multitasking in Mail: if you want to refer to other messages while you're composing mail you can swipe the message down, browse your email to read or copy, and swipe it back up when you're ready to continue.
That'll make complex replies on iOS much more convenient.
Smarter home apps
The new HomeKit API is designed to make iOS the hub for all kinds of smart home equipment. Instead of multiple apps doing their own thing, Apple has created a platform for locks, lights, cameras, doors, thermostats, plugs and switches that groups devices together and controls them via Siri - so telling Siri "ready for bed" would turn off the lights and heating, arm the alarm and kill the TV.
If HomeKit is widely supported it could turn out to be a very big deal.
The new Metal graphics system delivers console-quality gaming on iOS devices, and the demos were genuinely jaw-dropping. Metal is iOS-only, which could mean developers writing more iOS-exclusive titles and not porting them to other platforms.