Currently, the Obsidian app allows you to specify how you want to open notes — either in the editor in in preview. I think it would be useful to have two settings — how to open new notes and how to open existing notes — each of which could be independently set to “editor” or “preview”.
will do 
…actually, the issue has already been reported, and the thread states the feature was implemented in 0.10.1, but I don’t see it in 0.11.x.