Well I thought this was a straight-forward thing, one product taking over from where another left off. But apparently not.
One pretty knowledgeable website is http://modernfirearms.net/index-e.html. Although small arms are not something I typically read up much about, sometimes the development or history of a particular weapon (AK-series for example) makes for some really interesting reading. And the bonus is that this website is also updated when new information has been verified.
Getting back to the subject, I figured that this "MA" weapon was some kind of prototype/pre-production designation for the replacement to the AKS-74 compact assault rifle/carbine which has been in service since the 1970's as both a personal defence weapon for vehicle crews and supposedly for the airborne units/spetznaz as well.
The AKS-74U entry on that website however, now disputes this, saying that some AK-105 is now replacing the former weapon since no AKS-74U's have been produced in Russia since 1997.
So is the AK-105 an interim solution until the "MA" or whatever it is likely to be called - is available in numbers? Will the "MA" ever see actual service? Or will this be another weapon like the AN-94 which is supposedly in limited service with some law enforcement agencies but the military at large never seems to take any delivery of?