Today, Apple is holding another one of their keynotes, where they will probably announcing some new shiny cyber doohickey. But exactly what shiny doohickey will be revealed? Here are the possibilities.

Definitely A Sure Thing Unless The World Ends

iPhone 5S: It's right around that time of year when Apple releases a new iteration of their iPhone, and this year is a half-step, keeping in line with the tick-tock release schedule (alternating numbered and 'S' models) that the company has maintained for the last few year. While the new model will likely have the requisite processor and camera improvements, other features such as a fingerprint scanner are more speculative. Leaked photos also show that the models may come in more colors than white and black, including a flashy champagne gold.

Highly Likely

iPhone 5C: The fabled "cheaper iPhone" rumors have been around for years but those rumors might finally come to fruition in the form of a lower-end model. It's unknown exactly what this device will lack that the 5S will not. In the past, Apple has simply dropped prices on older models.

iOS 7, OS X Mavericks: The annual updates to Apple's mobile and desktop operating systems, respectively, will probably receive more specific launch dates than the broad "fall 2013" window previously supplied. iOS 7 will bring an all-encompassing aesthetic redesign to the system—AT&T  has apparently been prepping customer support reps to deal with blindsided customers—as well as new features including the Pandora-copying iTunes Radio. OS X Mavericks will also have a bunch of new stuff but really the only thing that matters here is that Apple has fixed the issues with multiple displays that have persisted for two years.

Jony Ive Talking About Chamfers or Something:  Sir Ive, set against a white background, will probably tell you that it's the best thing Apple's ever made or whatever.

Uh, Maybe?

Something about TV: While speculation has persisted that Apple finally figured out TV, there is unlikely to be any new hardware. More likely is a software update for current Apple TV boxes, which has been adding more and more streaming services over the past few months.

Mac Pro: This probably won't eat up more than a couple minutes of time, but the oft-neglected Mac Pro, which is seeing its first substantial update in nearly a decade, might get a solid release date.

Probably Not

iWatch: Despite Samsung's announcement of their entry into the smartwatch game, Apple is probably not going to announce any wearable technology. They're not a company that rushes things out, and two substantial hardware announcements in one keynote would probably spread conversation thin.

Phablet: An ugly portmanteau of "phone" and "tablet," rumors circulated this week that Apple was experimenting with 6-inch screens on their phones. Maybe next year, but Apple's pattern of alternating between internal and external revisions will probably hold up for now.

Admitting Total Complicity In PRISM: That would be nuts though, wouldn't it?

The keynote begins Tuesday at 1 p.m. Eastern, 10 a.m. Pacific.