The "iPad Pro" is said to be an even larger version of the iPad Air, with a display measuring in at 12.2 to 12.9 inches. Perhaps aimed at the enterprise market, it may feature an ultra high-resolution display and an A8X processor.
Apple is planning to expand its iPad lineup with a larger tablet, which the media has taken to referring to as the "iPad Pro." Expected to measure in at 12.2 to 12.9 inches, the iPad Pro will be Apple's largest tablet, dwarfing both the 9.7-inch iPad Air 2 and the 7.9-inch iPad mini 3. At 12.2 to 12.9 inches, the iPad Pro would be closest in size to the 13-inch MacBook Air.
While rumors on the larger iPad are somewhat scarce, it's believed the tablet will closely resemble the iPad Air 2 and the iPad mini 3, offering a thin chassis and slim bezels. The iPad Pro may measure in at 7mm, and it will likely include several iPad Air 2 features like an A8X processor, 2GB of RAM, Touch ID, and 802.11ac Wi-Fi.
It may also ship with an "ultra" high-resolution display and speakers and microphones at both the top and bottom edges of the device, creating an improved stereo audio experience.
Rumors of a larger iPad first surfaced in mid-2013, suggesting Apple was working to expand its iPad lineup with a bigger offering aimed primarily at its enterprise customers.

News of the iPad Pro's development continued throughout 2013 and early 2014, but slowed somewhat in mid-2014 after rumors indicated Apple had shelved the project to focus its work on other products.
In August, news of the iPad Pro surfaced again, with Bloomberg indicating that Apple would launch the larger-screened device in early 2015 in an effort to "shake up the iPad line" and boost declining sales, but an October report from The Wall Street Journal suggested Apple was delaying mass production of the tablet to produce more iPhone 6 Plus devices.
In November, KGI Securities analyst Ming-Chi Kuo suggested that improving component yields for iPad Pro's high-resolution oxide LCD panel would take some time, pushing mass production back until the second quarter of 2015 and thereby delaying the tablet's launch until later in 2015.
Early rumors pointed towards a 12.9-inch display with a resolution of 2732 x 2048 and 265 pixels-per-inch (ppi), but more recent rumors have suggested the iPad Pro might be 12.2 inches rather than 12.9 inches.

News from the Asian supply chain has suggested that the iPad Pro will offer a higher pixel density than the iPad Air 2, nearing high-definition quality.
The iPad Pro will likely adopt many of the design elements found in the current iPad, including an ultra thin chassis and narrow side bezels. Apple has been hard at work slimming down its products, and the iPad Pro may measure in at 7 mm, which is slightly thicker than the 6.1 mm iPad Air 2 and the 6.9 mm iPhone 6, but slightly thinner than the 7.1 mm iPhone 6 Plus.
According to rumors, the iPad Pro will ship with the triple-core A8X processor that was introduced with the iPad Air 2. Positioned as an upgrade to the A8 processor that was introduced with the iPhone 6 and 6 Plus, the A8X offers some significant performance improvements. According to a Geekbench 3 multi-core benchmark, the A8X processor in the iPad Air 2 is up to 55 percent faster than the A8 processor in the iPhone 6 and 6 Plus.

The iPad Air 2 was the first of Apple's mobile devices to ship with 2GB of RAM, and it is likely that the iPad Pro will also include 2GB of RAM.
The iPad Pro is may adopt many features found in the iPad Air 2, including 802.11ac Wi-Fi, which is twice as fast as 802.11n Wi-Fi, and LTE Advanced in Cellular + Wi-Fi models, taking advantage of carrier aggregation to offer LTE connection speeds of up to 120 Mbps.
Like the iPad Air 2, the iPad Pro will probably offer a motion coprocessor with several sensors, including a gyroscope, accelerometer, GPS, barometer, and compass functionality, and while it's likely to gain a front-facing FaceTime HD camera, a rear camera is somewhat more questionable as such a large device would not be particularly portable.
Touch ID, which Apple has been building into all of its mobile devices since the iPhone 5s, will almost certainly be included with the iPad Pro both to enable Apple Pay in apps and to add the convenience of unlocking the device with a fingerprint.
According to rumors, the iPad Pro will include speakers and microphones on the top and bottom edges of the device, offering an improved stereo audio experience.
Apple's iPad Pro is expected to ship with a version of iOS 8, the company's newest operating system that debuted in September. Apple may be planning to introduce some upgrades to iOS 8 that could come alongside the launch of the iPad Pro, including split-screen multitasking.
The company is reportedly developing split-screen multitasking with both the iPad Air 2 and the iPad Pro in mind, allowing users to run two apps side-by-side on a single screen. Code suggest the two apps could either split the screen half-and-half or one could take up 3/4 of the screen while the other runs in the remaining 1/4.
Split-screen multitasking was not ready for iOS 8's release, but it could come in an iOS 8.2 or iOS 8.3 update, both of which Apple is working on.
A questionable rumor has suggested the iPad Pro could offer an iOS/OS X hybrid operating system, but this is unlikely as Apple executives have said time and time again that there are no plans to integrate iOS and OS X.
An image said to depict an iPad Pro dummy used for creating cases and other accessories surfaced in May, and while the legitimacy of the model can't be confirmed, it does give a look at how a larger 12.9-inch tablet might look in-hand.

An August report from Bloomberg suggested Apple planned to release the iPad Pro in early 2015, but an October report from The Wall Street Journal indicated that Apple delayed its planned December mass production of the larger tablet in order to focus its attention on producing more iPhone 6 Plus units to meet demand.
At this point, it is unclear if Apple is still on schedule for an early 2015 release or if the iPad Pro's launch will be pushed back until later in 2015, but KGI Securities analyst Ming-Chi Kuo has suggested that difficulties ramping up display components will prevent the tablet from entering mass production until the second quarter of 2015. That means the tablet would not see an early 2015 release.