Apple may have leaked a tutorial guide detailing their iPad Air 2 and iPad Mini 3, but the company is expected to officially unveil them anyway Thursday.

The new tablets are the headliners of the event, but Apple is also expected to release OS X Yosemite, the desktop operating system that will bring about iOS connectivity. Also expected to debut are new iMacs with Retina HD display.

Apple will be airing its event live online. It is set to begin at 10 a.m. on the West Coast, 1 p.m. ET. Here is what to expect:

1.     iPads

Apple has experienced a decline in iPad sales for two consecutive quarters, but the major shakeup to their line of tablets is not expected to happen this year. The Wall Street Journal reported previously that a 12.9-inch iPad will go into mass production in 2015. The larger iPad could be a business-centered 2-in-1 device with an OS X - iOS blend operating system.

As for the tablets Apple will be unveiling, 9to5Mac has screenshots of the accidently released iPad user guide.

2.     Computers

Re/Code's John Paczkowski learned that Apple will be delaying the Retina display MacBook Air, but is planning to unveil a new iMac with the ultra-crisp display. The MacBook line may have to wait for a major upgrade, but the iMac was already overdue for one.

3.     Software

Thursday may be the day Apple Pay arrives on the iPhone 6 and 6 Plus, but the event will definitely usher in the new desktop operating system. OS X Yosemite will give Apple's computers the same look and feel introduced with iOS 7 and will also bring about more connectivity between the two operating systems.

4.     TV update?

NBC News noted that Apple is also overdue for an update to their TV player to keep up with Roku and the Kindle Fire TV device. Rumored to be in production, yet unclear if it is ready for release, is an Apple smart TV set. The devices are on the rise in popularity and Apple is known to be working on an OS-connected home.

What would complete that better than an iOS-controlled television?