I think my One Page Dungeon Codex came out fairly quickly, although this was before they made you estimate delivery: http://kck.st/9oJ3jq

And the Miskatonic School for Girls was actually a bit early, shipping in March when it was estimated for April: http://kck.st/rlbUrH

I'll admit I usually assume that the estimated delivery date is an early bound on the time range when it will actually be delivered.