Apple hasn't skipped a beat with its annual iPhone and iPad updates, so there's little doubt that it'll be called iOS 9 and launch in tandem with the new iPhone.
But that's months away. iOS 9 is likely to be previewed well before the iPhone 6S unveiling, specifically at this summer's World Wide Developer's Conference.
iOS 9 is due to take center stage at WWDC 2015 with feature announcements and, of course, a beta made available to anyone with an Apple developer account.
Here's what we know so far about iOS 9 and what we're hoping to see in a few months times.
iOS 9 release date
Apple has confirmed the dates for its Worldwide Developers Conference in San Francisco where we're expecting to see iOS 9 shown to the public for the very first time.
The event will take place at the Moscone Center between June 8 and June 12 this year with rumours suggesting Apple will also be debuting its Beats music streaming service at the event as well.
From there we can fully expect registered Apple developers to get their hands on the iOS 9 beta soon after. We expect the rest of the public will have to wait until September this year to download it again as the company has done in the past.
That three-month wait can be a good thing. iOS 9 beta 1 will be buggy and unfinished. The best features typically don't launch until the gold master version in September anyway.
iOS 9 compatibility
This may be the first iPhone and iPad software to require a lightning cable connection, at least if it follows the current trend among Apple smartphones.
iOS 8 muscled out iPhone 4 compatibility last year, and iOS 7 said goodbye to iPhone 3GS two years ago. Is iPhone 4S on the iOS update chopping block?
That makes sense. After all, the company is gearing up for its lightning-port-required Apple CarPlay infotainment system.
On top of that, iPhone 5 and iPhone 5C first introduced 1GB of RAM, up from the 512MB in the iPhone 4S. It's time to retire these 30-pin dock devices.