I guess that on Friday 29:th April we will see a black tie evening with just the swedish royal family, Sommerlath Family, Westling Family, Hellqvist Family, O'Neill Family, parliament and government.
Saturday 30:th April we will see a white tie evening with royals, presidents, ambassadors, politicians etc.
On Sunday 1:st May i guess there will be a service of thanksgiving in the Royal Palace Church and a following farewell lunch at the Palace.
Based on how the 50:th and 60:th birthday celebrations have been, This is how i guess it will be. But ofcourse it can be smaller or bigger.
I'm sure that the danish and norwegian royal families will attend (minus Prince Henrik) as well as the Finnish and Icelandic Presidential Couples. Would be nice to see the other european heads of state too.
Maybe Albert and Charlene will attend as Albert are close to the swedish royals. I also expect the titular Greek royal family to attend as well as the titular german ducal families of Sachsen-Coburg, Gotha and Bavaria.
I am sure it will be an interesting weekend anyway.
If Silvia wears the braganza tiara, that would open up a small chance of seeing Victoria in the Cameo tiara or Nine prong tiara. But to be realistic i expect her to wear one of "her main tiaras".
I guess Margrethe, Mary, Benedikte and Anne-Marie will all wear former "Bernadotte tiaras. I'd say Margrethe in the Baden Palmette Tiara, Mary in the Ruby Tiara, Benedikte in the Star and Pearl Tiara and Anne-Marie in the Khedive Tiara. Don't think Joachim and Marie will attend.
For the same reason i guess Sonja will wear the emerald parure or Queen Josephines Diamond tiara. I would love if Mette-Marit could borrow the Vasa tiara from Princess Astrid. Would love to see Astrid herself there too, wearing her famous "Antennas"