Devices marked with a * are unconfirmed, and may have different names - or never launch at all. I've only put one entry for the new iPhones, but there's a decent chance we'll see more than one: perhaps an iPhone 6c and an iPhone 7? Opinions on this are divided in the Macworld offices.
What's our thinking with these predictions? Well, iPad compatibility has historically moved upwards quite slowly: the iPad 1 was the bottom rung for three versions of iOS/iPhone OS, and now the iPad 2 has done the same. The iPad 2 has also been recorded as suffering some speed issues with iOS 8. We think its time has come.
The iPad minis are harder to predict, because we've got no historic data to go on: all three iPad mini models run iOS 8, and we have no idea how long Apple expects them to last. But the iPad mini 1 is starting to feel pretty slow compared with the two newer models, and could well drop off compatibility with iOS 9.
iPhones tend to move quicker, lasting as the bottom rung for one or two versions. The iPhone 4s has been bottom for only a single version (the iPhone 4 could run iOS 7) but plenty of people have claimed that iOS 8 slowed down their iPhone 4s handsets. We don't expect the 4s to be able to run iOS 9.
And finally, it would be a dramatic move for Apple to remove the iPod touch line entirely from iOS 9 compatibility, so this may depend on whether Apple updates the iPod touch. If it doesn't, we'd expect the 5G iPod touch to remain compatible with the latest update.
iOS 9 rumours: Images, screenshots and concept videos
It's very early days, and we don't expect leaked screenshots to start appearing for a while yet. But a few designers and artists have started coming up with design ideas for iOS 9's interface.
It was said that the rectangle with rounded corners was Steve Jobs' favourite shape, and we've all been tapping rounded-square icons for so long that circular icons just look wrong - but also radically new and vaguely exciting.
The primary-school mathematician in me feels the need to point out that circles tessellate less effectively than squares (and even rounded-corner squares) and the above system reduces the available space for developers to design in. But we're used to circular icons in Mac world - iTunes, the Mac App Store, most of the browsers - so why not?
iOS 9 features wish list
So much for the rumours and speculation about when iOS 9 will launch, and which devices it will run on. But what features can we expect in iOS 9? Hopefully Apple will include some of these:
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