Regarding multiple iterations: I really need to get a list up somewhere, and keep it up-to-date, of what features would be for what iteration. Thus far I can see a "ready-to-start-implementing" (at least authentication and posting and editing entries. Call it feature-parity with the Blogger API.), a "viable prototype" (enough features to actually be useful, so that's fetching comments, basic full-dump style backup, reading page), "idealised basic" (add posting and editing comments, treating them as first-class objects, icon management), "solid" (account settings, moderation tasks, &c), "polished" (everything one can do through a browser, even if it takes multiple calls under-the-hood), and what one might call "wishlist" (things that exist purely to lighten server load and allow people to make little toys).

I may be subdividing a little too finely, here, but I think the principle's sound.

I should get on that.