Cofounder here -- just want to let people know that we STRONGLY believe that your data shouldn't be trapped in a SAAS application.
Roam does allow you to export all your data to an org-mode file (the emacs outliner), we're working on other import/export options, and want to get to the place where there is a close to plain text representation of your Roam workspace on your file system that syncs both ways.
We weren't expecting someone to post us to HN yet. This is a case of, if you're not embarrassed on launch, you launched too late. Just want to let y'all know we dont believe in SAAS lockin for a tool for thought, and data portability for the folks who aren't emacs users is coming.