Carthain said:
But [WotC sources] have specifically said that they want the gametable to be generic so that it can be used with ... games [other than 4e].
Well, yes and no. If you're a d20 company, and you put out a book of monsters, you won't be able to provide virtual miniatures of your monsters to use. If you've got variant races, you won't be able to make those available to PCs. If you've got variant weapons, the PCs won't be able to be shown with them, and so on.
So while you could play a game set in Freeport (using only D&D monsters), you'd have a difficult time playing [Arcana Evolved] or Dragonmech.