Not trying to start a scale war, but they seem to really getting new runs/new tooling for HO locomotives out the door pretty regularly right now (I get their emails for new announcement)- if I had to guess, the margins on HO DCC Sound locomotives are a lot better than N scale freight cars and they are allocating their time/resources accordingly.
I say this as someone who could really use several of their announced 70 Ton covered hoppers, but I don't expect them terribly soon.