Even in an industry that thrives on change, what are we without our traditions? In keeping with what's quickly becoming a bankable schedule, Apple (AAPL 0.64%) recently confirmed that it would again use the second week of September for the third-straight year to unveil its next-gen iPhones -- the iPhone 6s and 6s Plus.

However, many feel Apple will also use the much-watched Sept. 9 event as a platform to unveil at least one additional substantial product update, so let's review what additional products Apple might have up its sleeve next week.

Expect an Apple TV update 
Perhaps the most high-probability non-iPhone 6s product the analyst community expects Apple to introduce is an improved version of its Apple TV product. How much an update would advance Apple's overall TV business, though, remains far from certain.

Without question, the most widely discussed aspect of Apple's television ambitions is its highly publicized, but hitherto unannounced, attempts to launch its own branded over-the-top streaming broadcast television service. According to recent reports, Apple's TV efforts have stalled of late, making the likelihood low that Apple will have this much-discussed aspect of its TV business waiting in the wings for next week. More likely, Apple's streaming TV product won't debut until some time in 2016, if at all.

Aside from content, Apple TV should receive a few internal hardware updates, including the A8 chip that powers Apple's current generation of iPhones, and larger memory capacity. And on the software side of the product, persistent rumors also claim the device will feature an upgrade to the company's Siri digital assistant, although concrete details as to what exactly that entails aren't clear. 

Although the delay of its over-the-top streaming service deals a blow to the short-term consumer appeal of Apple TV, the device likely remains an integral piece to an important long-term growth opportunity for Apple -- the connected home. Perhaps as a pre-emptive counter to Apple's upcoming TV, Google recently launched its own OnHub Wi-Fi router. It appears that it will also serve as a possible entry point into that company's bigger picture smartphone ambitions.

Apple enjoys its own smart home technology in HomeKit, but like Google, it needs to cultivate an actual installed base of in-home hardware in order to position itself as a hub or platform for the connected home of the future. Apple TV sales are lumped into its Other Products reporting segment, along with other items like iPods and Apple Watches. As such, gaining any reliable visibility into the direction of Apple TV shipments is a fool's errand. However, at a high level, this update to Apple TV should help the device remain competitive against similar products.

Other possibilities
Things grow far less certain from here. Word consistently surfaces that Apple might also use the event to debut its widely rumored iPad Pro. However, with Apple typically opting to debut its next generation iPads at an independent event in October, this course seems a bit hard to reconcile. Especially with its iPad lineup sorely in need of some positive media attention, risking the iPhone 6s overshadowing the iPad Pro seems more reckless than calculated.

Apple very well could provide some additional information about the Watch, although an entirely new iteration of the Watch isn't likely. However, Apple might choose to provide a few data points on the overall health of Watch shipments, or some kind of usage data. Additionally, it would make plenty of sense if Apple uses the event to provide more concrete specifics on when it will actually open its watchOS 2 software this fall. 

With the iPhone providing the bulk of Apple's sales and profits today, it only makes sense that Apple will use the majority of its upcoming event to showcase what has quickly become its marquee device. Whether Apple's forthcoming iPhones will help maintain consumer interest to maintain the tech giant's torrential business momentum during the past 12 months will likely prove the defining storyline for Apple investors in the year ahead.

With only days to go between now and the start of Apple's product launch window, analysts and investors will have their answers soon enough. Make sure to check back for all our Foolish commentary about one of tech's most important annual events.