The excitement comes, however, amid a slew of leaks that have all but eliminated any sense of surprise as to what the updates will entail.
As late as Sunday night, an image of the new iPhone 5S's packaging, complete with a photo of the rebuilt home button, surfaced online. A thin silver line around the black button appeared to further confirm the near-certainty the new device would include a fingerprint scanner in the button.
Also expected are an upgrade to the phone's processor chip, with the A7 running significantly faster than the iPhone 5's A6, and improvements to the camera.
The new iPhone will get a significant facelift, adding a gold color option and shipping with the iOS 7, a redesigned software interface that developers have given positive reviews since it was released in beta earlier this summer.
The iPhone 5C, which is feature a plastic casing instead of metal but otherwise resemble the iPhone 5, will come in a range of colors in addition to its smaller sticker price.
Apple often (but not always) streams the event live to Macs and iOS devices, but generally doesn't make the information available until the day of the presentation. Watch this space for updates Tuesday, and in the meantime, flip through the slideshow, above, of the leaked images.