For the past 2 years, Apple (NASDAQ:AAPL) has hosted separate events in September and October, spreading out product unveilings over the course of those months and dominating headlines and media coverage. October 16 is the date this year to mark on the calendar.

There are some obvious candidates of what to expect at the event, but there's also room for speculation about other products that Apple could show off. Let's start with the most likely headliners.

New iPads
Apple shifted its iPad product cycle in 2012 to fall releases. That was the year that Apple introduced the first-generation iPad Mini. Ever since, Apple has unveiled new tablets in October, and as such should do likewise this year with a new iPad Air and new Retina iPad Mini. Both new models are expected to get Touch ID sensors integrated into the home button, after the technology was introduced in the iPhone lineup last year.

The iPad Air 2 is expected to have a very similar overall design to the current iPad Air, with only minor changes. Apple could add an anti-reflective coating to the display in order to make it easier to read in direct sunlight. Apple is rumored to be adding a gold color option to the lineup this year as well, which would mirror the iPhone portfolio, which would mirror the iPhone portfolio. Spec bumps like a faster A8 or A8X processor and potentially more RAM could also be in store.

For the most part, the second-generation Retina iPad Mini is also expected to get most of the same upgrades as the iPad Air 2, with little if any design changes. However, there is a possibility that the second-generation Retina iPad Mini will be delayed until early 2015.

Code found within the iOS 8.1 beta that was distributed to developers hints that Apple will facilitate Apple Pay in the new iPad models. While the new iPads are not expected to carry NFC chips for use at retail locations (who carries around their tablet all the time?), Apple Pay will enable developers to accept payments in their apps as well as online purchases.

There has been considerable speculation that Apple is preparing to release a 12.9-inch "iPad Pro," but rumors suggest that this product will be unveiled in early 2015, if at all.

OS X Yosemite
The next major version of Apple's desktop operating system will almost undoubtedly launch this month. Announced this summer at Apple's developer conference for availability "this fall," OS X Yosemite features a massive aesthetic makeover that resembles iOS. Apple has already detailed all of the major new features in OS X Yosemite, so there aren't likely to be any surprises as far as features go.

Technically, the primary unknown with OS X Yosemite is the specific timing of the release. The company has already released the "golden master candidate" version of OS X to developers and participants of its public beta program, which is the final version before it is ready for widespread distribution, so the release is imminent.

With new iPads and OS X Yosemite all but certain for an October launch, let's turn to the products that are less certain.

Retina iMac
Apple has reportedly been working on a high-resolution version of its all-in-one iMac desktop. Hints of the "Retina" iMacs were first spotted this summer in early beta versions of OS X Yosemite.

The company may increase the resolution of the 27-inch model from 2,560 x 1,440 to a 5,120 x 2,880 panel, following its "Retina" strategy of doubling pixel dimensions. That would classify the display as a "5K" display. The smaller 21.5-inch model is expected to keep the same resolution.

The desktop is expected to feature high-end Intel Haswell processors as well as state-of-the-art AMD graphics. That would represent a switch in discrete graphics chips providers, as NVIDIA is Apple's current vendor.

Mac Mini
One of the least loved products within the Mac family is easily the Mac Mini, which hasn't been updated in 2 years. Sitting at the lowest price point for Macs, it makes sense why it gets the least attention from Apple. That being said, it's about time to update the smaller desktop.

Not much else is known about the possible Mac Mini refresh, but it stills seems entirely possible that one will take place this year considering the aging internals of the current models.