It's been a bit more than a month since we buried our yard in compost. And apparently the whole experiment has been successful because we now have a green lawn with no weeds:
We're marking this down as a successful project! To recap, we aerated, raked up the roots of as much weed on the slopes of our yard as possible, seeded heavily, spread several inches of composted leaf mulch until there was no visible lawn left, seeded heavily again, raked, seeded more. In the spring we may treat with a weed killer, even though we really try not to use any chemicals in the yard. We'll test the soil and spread more lime if necessary and add a natural fertilizer.
Now we're just wondering how much time we have until our new lawn is buried in feet of snow.