I'm more than positive we'll be getting Filmation characters in time.
ToyGuru has specifically mentioned that they're trying to space heavy hitters out over time so all the best stuff doesn't get released at once....so we hear we're getting Panthor, King Hiss, and Swift Wind in '11...and everyone gets depressed that we've heard nothing of Shadow Weaver or StrongArm.
C'mon, people! Masters of the Universe Classics is a major experiment on Mattel's part...one that--suffice it to say--has never really been tried on such a grand scale by any other company. And that experiment...is succeeding beyond everyone's wildest dreams.
They'll reveal Filmation stuff in time, but I don't think they believe it's necessary just yet. And based on the look of the Shadow Beast, I'm under the belief they have the license already.