The more I think about "OmniNotebook" (or "OmniProject"?), the more I like it.
I love the clean manner in which an OO outline expands and contracts to show (or hide) elements of the outline as needed. But when an outline becomes very long (as mine often do), and I want to only work on one small section of that outline, I face a set of unappealing choices: stare at the whole outline (which is distracting); or, break the outline into separate, smaller OO files, which I must then track independently yet try to keep synchronized with the main one; or, scroll through the whole thing, clicking on triangles to open/close various elements; or, move the subsection into an altogether separate program (like Scrivener) and now shuffle between the two apps.
A "notebook" approach would solve this dilemma nicely. It might offer to convert the subsection into a separate page, accessed via a tab, so I could work on it without facing the whole gangly outline. Or perhaps the main outline (which would remain, and continue to grow, on its own page, as the "backbone" of the project) would sprout a hyperlink to the new page, rather like in VoodooPad. In addition, I could add different kinds of pages to my project: a stripped-down OmniFocus page, to track project-related to-dos (but which might also link to my main OF database); a stripped-down OmniPlan page, to track project-related deadlines; a page for managing data elements or source material; maybe a stripped-down OmniGraffle, if I want to manipulate my outline in something like a mindmap view.
From Omni's end, I'd think "OmniProject" could offer a way to integrate elements of the other Omni products -- an addictive gateway app, as it were. (I note some interest in trying to integrate OF and OP in this thread:
http://forums.omnigroup.com/showthread.php?t=7949). Ideally, OmniProject would just be a simple platform, and a way for the user to easily snap together elements of Omni's other excellent programs.
The trick, of course, is knowing where to stop; OmniProject could easily morph into a sweeping, confusing, kitchen-sink-style app. (Curio, anyone?) Then again, done in elegant Omni fashion, such a thing could totally rock. I notice that there's a new version of Tinderbox out ... and it's *still* ugly as sin ...