I just had my visa interview in Sweden. From our NOA2 date it took USCIS 1,5 months to even send the case to Department of State, so I would advice you to not count on anything happening until the status says "Sent to the Department of State". After that it took almost another 1,5 months until my fiance got the checklist from the embassy with everything we needed to do. This e-mail will include the case ID you need to have in order to even start the DS-160.
We finished the DS-160 about a week after that, and only when you're done with the DS-160 and have paid the fee you'll be able to schedule the interview. My earliest date was 2 months out, I'm not sure if Christmas had anything to do with it since I scheduled in end on November and the earliest time was end of January. I think Sweden started taking on cases for a bunch of other countries since December so the timeline might have changed. Also, I didn't schedule my medical exam until I had a interview date, since the medical exam is only valid for 6 months from the exam date, and it has to be valid at the time of entry. I had my medical exam a week before my interview, it was not enough time for the embassy to receive it before my interview. I got told my visa got refused but only because they didn't have the exam yet and if it shows no ineligibility they will approve it. The doctor e-mailed me my copy of the vaccination sheet the same day as my interview so I think if I had left a little more time between the medical exam and the interview I'd have an approval on the spot.
Also, good thing to know about Packet 3. It was not sent to my e-mail, it was sent to my fiances e-mail and said to forward it to me.