Just thought i'd share this information - since I was looking for it myself and couldn't find much. I recently bought two iPads, one was week 17 (extremely early), the other week 30 (kind of late). I got them both from Target. Both had 4.3.3 installed. So i think its safe to say week 17-30 are all 4.3.3 I couldnt find this information anywhere myself - so at least now its here for anyone who needs it.