With tha latest news of AK-12 being accepted as one of the weapons of choice for russian army, it would be good to list a few differences from the AK-74M.
First of all and most notable is the improvement in ergonomics. It is possible to perform most manipulations with tha gun with a single hand. Notable is the ambidextrous fire selector(with burst fire added), which is easy to use with a thumb, absolutely new to AK series, and a new magazine release. It is now possible to drop the mag with the help of a single finger. Also AK features new ventilated handguard and a foldable telescopic stock. As for the other notable improvements, AK-12 features a new compensator and a new receiver cover.
A couple words abouth the cover. It is far more hard and got rid of the backlash problem, which is usual for any AK. Moreover, it features a picatinny rail, and new sights, with a longer sight line, that should considerably increase iron sight fire accuracy.
The system is left classic, with a couple improvements to the manufacturing process. The parts are made with far more precision.
The price, voiced by IZhMASh, is $1000. The gun should be availible by spring-summer 2015.

Every part of the russian gear for the "future soldier", Ratnik, is picked. Except the main thing. The gun itself.
That was until the state test, which was suposed to show the #1 among the contenders. Two opponents were the new AK-12 of the "Kalashnikov" concern and the A-545 made by Degtyarev factory. And both passed the test. Both rifles meet the demands of the russian Ministry of Defence.

It seems, that Russia will be adopting both guns, but arming different departments, as the guns have different characterstics, despite the similarities.

A-545 has better automatic fire accuracy, because of innovative balanced automatics. On the other hand, the AK-12 is easier to manipulate and easier to maintain, because of quite simpler build.

Reminding, that the use of "Ratnik" will start at march of 2015 and until that time, the guns will be picked