Yes but the Infinite Staircase modules aren't an AP. They are a handful of very generic modules that has a frame device IF you want to use it. The DL modules aren't. They are hard to drop into another setting as they are so keyed to DL specifics (such as the Dragon Armies and draconians).
I feel like I'm blue in the face, so I'll just leave it at this: I don't think that the DL series is coming this December. The evidence for it is flimsy. The evidence against it is better. Could it happen? Sure. We could also get another Media Tie-In, another MTG setting, or a My Little Pony Monster Compendium too, and I give them all about equal chance.