93-97
You guys have to realize that the people who review games are well aware that it's a fighting game. A first person shooting game isn't judged on how many things you do outside of first person shooting, it's judged by the gameplay and elements of the first person shooting.
They're going to judge this Mortal Kombat as a fighting game, and as a fighting game it delivers on a bunch of fronts. It's appealing to the eye, it's friendly to pick up, and it has alot of content that deals with the fighting engine.
MvC3 got 8s on average and (no offense to MvC3 of course) the game is pretty bare boned when it boils down to it. The story mode is lackluster and the Arcade mode and online modes are equally as lackluster. But the reviewers judged it for its main fighting engine, and it that itself made it loved by many.
MK has a boat load more crap than MvC3 will ever have AND has a solid and emersive fighting engine. It's pretty safe to say it'll at least score 90% or better by practically all reviewers.
Some of you might say that it's stupid for people to review a game before it's released but for fighting games its alot different. Fighting games wear what is good about them right on their sleeve. If you know how the game plays, the other stuff added to it is just icing.
It's clear that MK9 is a good fighter. So we should already know it'll score well above 85% generally.