The answer seems to be yes, if hints in the latest development version of iOS are to be trusted. A 12.9 inch "iPad Pro" may be released this year.
At 12.9 inches, the iPad Pro's screen would have 76% more screen area than the iPad Air, and 170% more than the iPad Mini. Coupled with enhanced multi-tasking features in iOS9, the larger screen would enable higher productivity.
Rumours of a bigger iPad have been swirling around technology blogs for a number of years. The premise of a 12.9 inch iPad was tantalizing enough for the rumours to circle repeatedly without proof. Finally, we have some information to substantiate the rumour.
9to5mac reports the iOS9 beta released last week contains hints of support for a larger screen. The iPad's on-screen keyboard now supports unprecedented screen resolutions, and the key layout at higher resolutions is significantly redesigned.
If that wasn't enough, the iOS9 keyboard code explicitly defines a new keyboard size of 1366x372, which is consistent with a larger 12.9 inch iPad. (Current full-size iPads are 9.7" with a keyboard size of 1024x283.) This is a fairly blatant hint at Apple's plans for the next version of iPad.
Apple has a history of keeping its cards close to its chest. This makes us think that the hints revealed here indicate an imminent release of the 12.9 inch iPad -- in the next upgrade cycle in October 2015.