. . . I suspect it will be the equivalent of MM6 v1.2 with an updated Mok's patch. It would be stupid of them not to make the game fully compatible with Win 7 & 8, and to get rid of the two door bugs that were the Achilles heel of the official v1.2 patch.
I know MMX has been issued by a different company, but when 3DO put out the MM6 Limited Edition, they got rid of all the bugs in MM3. In the original game, there were four positions just north of the Tomb of Terror which used to crash my computer to the point at which all I could do was turn it off, and those were cured in the version that came out with MM6. I have to say that they didn't succeed in debugging Swords of Xeen completely, though. I could never complete that last dungeon in that game.