Via the Rocky Mountain News Twitter feed, it seems the Denver Post wouldn’t allow it:

Contreras says that agreement couldn’t be reached.about 19 hours ago from TweetDeck Contreras says for Rocky to continue as online-only product , the partner in the JOA – Dean Singleton’s Denver Post – would have to agree.about 19 hours ago from TweetDeck Question: Why not start an online-only edition. Contreras: If we thought we could do that, we would not be here today.about 19 hours ago from TweetDeck