Hogie - although I'm personally against the idea of difficult levels (as Tobias said, too EA), the amount of complaints seen in GQ and (ahem) others about the game being stupidly hard, the cheating AI, the bugged game engine, etc. mean that SI may feel it could be the way to go in order to keep the game challenging for the hardcore, and make it accessible to the newbie/tactically challenged.
At the end of the day, they won't want to lose the casual user, as it is this market which will create new fans/addicts and generate growth of the franchise.
However, rather than having difficulty levels, I hope they make the 'core' game as hard as they feel is realistic, but provide lots of help for those that need it through things such as extended AssMan assistance, extended tutorials, better default tactics, etc. rather than watering down the difficulty.
That seems like a more suitable solution (and truer to the game).
inevitably as SI's code becomes more and more sophisticated as FM evolves, the difficulty will increase as a matter of course (subject to the limits set by the coders).
If you still master the game, then you could always use the
editor to give yourself a harder challenge...