OK, so here is what happened:
12:45 - I arrive at the embassy. There is one more person waiting.
13:05 - They start letting us in. I am inspected by a Polish-speaking security guard - what a nice surprise! I leave my mobile phone there, I get a receipt and a security badge.
13:45 - A nice lady takes my documents (small fraction of what I brought). I am told that the system sometimes refuses to accept B&W photos. However, mine seem to be just fine. I pay the fee, it's 85 euro, not 80, contrary to the information in Packet 3.
14:05 - I have to promise that all the information I provide is true. I am asked three questions: Have you ever been to the US ? On what kind of visa ? Have you met your fiancee ? (yes, tourist visa, yes).
[waiting begins]
[waiting]
[still waiting]
15:30 - I and another K1 applicant are told that everything is fine, but our visas won't be ready until tomorrow. Apparently, they can't get Washington to answer whether I am a terrorist or not. I am supposed to call them tomorrow morning and hopefully they will tell me to come and collect my visa !
So basically everything seems to be fine, but I am not celebrating untill I have my passport and the visa in it !

Bartek