I would have loved to have a steel frame option...no question. But my guess is that a Ti hardtail will be offered as a lightweight alternative...even though an aluminum frame could be made much lighter than the current Fantom 29er frame.
It wouldn't surprise me if FS option were available as well.
My hope with a steel frame 29er is that they make an affordable one, something with a solid double butted Cro-Mo frame but it doesn't need to be the expensive (and IMO over-rated) Reynolds 853. It could easily be made with the very durable and good riding Reynolds 520 and the frame would only be about 1/2 lbs heavier but WAY cheaper than 853.
If they offer the frame alone, I'd seriously consider it. Otherwise, I'm figuring on picking up an On One, Soma, or Vassago steel frame next year.
I considered it, but I had a suspension seatpost ten years ago on a hardtail and I just am not a fan of them. I did go with a carbon post which does provide a small amount of comfort. Honestly, after riding full suspension bikes almost exclusively for the last 5 years...I just need to retrain myself to ride a hardtail again.