Moved up to Alpha 1 because doing so any later would require us to create all content again. Instead of every node getting a page later, all nodes get a page automatically. Further, only pages and unpageable nodes get URLs, so we can avoid the node-page URL conflict false positive, as well as the easily mismatches with category/group/book membership. Further, this relationship would allow us to have Book-ness or Category-ness as combinable add-ons to a page, though I don't personally see the point.
Not doing this and moving forward with the current Alpha 1 data management scheme would actually be a feature reversion since we already track title edits for Books and Categories, and leaving this until later would remove that ability.
Unfortunately this will be a slight setback since most content nodes will have to be reworked around the page node rather than all being separate entities, and all the spots that utilize them may need to be updated. I can't see this rework taking more than a few days to a week, however.
That said, I don't recommend starting on this until we have finished the other tests, templates, and plugins possible, since making this change will require a dev environment backup restore.