At York last fall that was one of the questions I was going to ask Mike Wolf. I saw him there alone but couldn't come up with any of the questions I had thought of before. My head was so dizzy from the show!
Considering the interest on this forum (albeit, a limited group), plus the price the previous releases command on auction sites, I would hope MTH would be able to produce another run.
As Doc mentioned though, and was brought up before, there is still the lingering agreement with Lionel Coporation and it certainly appears nothing other than Lionel or American Flyer will be made until this is done. too bad as I'm looking for a particular Ives engine too.