The list of confirmed participants as of 25 January:
• Armenia – Ashot Hovakimyan, Deputy Minister of Foreign Affairs
• Argentina – Patricia Beatriz Salas, Ambassador
• Australia – Josh Frydenberg, Assistant Treasurer
• Austria – President Heinz Fischer
• Azerbaijan – Elmar Mammadyarov, Minister of Foreign Affairs
•
Belgium – King Philippe I, Queen Mathilde, Prime Minister Charles Michel
• Belarus – Aleksandr Averyanov, Ambassador
• Bosnia and Herzegovina – Duško Kovačević, Ambassador
• Bulgaria – President Rosen Plevneliev
• Canada - Tim Uppal, Minister of State (Multiculturalism)
• Croatia - President Ivo Josipović
• Cyprus – Andreas Zenonos, Ambassador
• Czech Republic – Prime Minister Bohuslav Sobotka
•
Denmark – Crown Prince Frederik
• Estonia - Harri Tiido, Ambassador
• Finland – Speaker of the Parliament Eero Heinäluoma
• France – President François Hollande
• Georgia – Zviad Dzidziguri, Deputy Speaker of the Parliament
• Germany – President Joachim Gauck
• Greece – Tasia Athanasiou, ambasador
• Hungary – Zoltán Balog, State Secretary for Social Inclusion in the Ministry of Administration and Justice.
• Ireland – Charles Flanagan, Minister of Foreign Affairs and Trade
• Israel – Silvan Shalom, Minister for the Regional Development
• Italy – President of the Senate Pietro Grasso
• Latvia – The Speaker of the Saeima Ināra Mūrniece
• Liechtenstein – Aurelia Frick, Minister of Foreign Affairs, Education and Culture
• Lithuania – Linas Linkevičius, Minister of Foreign Affairs
•
Luxembourg – Hereditary Grand-Duke Guillaume, Hereditary Grand Duchess Stéphanie, Prime Minister Xavier Bettel
• Macedonia - President Ǵorge Iwanow
• Malta – President Marie Louise Coleiro Preca
• Monaco – José Badia, The Minister of Foreign Affairs and Cooperation
• New Zealand - Finlyson Chris, Minister of Culture
•
The Netherlands – King Willem–Alexander, Queen Máxima, Prime Minister Mark Rutte
•
Norway – Crown Prince Haakon, Prime Minister Erna Solberg
• Poland – President Bronisław Komorowski
• Portugal – Bruno Maçães, State Secretary for European Affairs
• Romania - Ioan Vulpescu, Minister of Culture
• Russia – Sergey Ivanov, Chief of the Presidential Administration of Russia
• Serbia – Aleksandar Vulin, Minister of Labour, Employment, Veteran and Social Policy
• Slovakia – President Andrej Kiska
• Slovenia – President Borut Pahor
• Spain - Jesús Posada Moreno, President of the Congress of Deputies
•
Sweden – Crown Princess Victoria
• Switzerland – President Simonetta Sommaruga
• Turkey - Mevlut Çavusoğlu, Minister of Foreign Affairs
• The United Kingdom – Philip Hammond, Minister of Foreign Affairs
• Ukraine – President Petro Poroshenko
• The United States - Jacob J. Lew, Secretary of the Treasury
• Vatican – cardinal Stanisław Dziwisz
The UK will be represented by Philip Hammond, the foreign minister, who is of a higher profile than Mr Pickles. Still not enough IMO.
Spain is an another major monarchy sending a high-ranked politician rathern than a member of the RF, and will be represented by its President of the Congress of Deputies (the lower house of Parliament), who is the second non-royal in Spanish order of precedence.
To sum up, there will be 15 heads of state attending, including 2 kings and one Acting President (Pietro Grasso of Italy).
Here is the full schedule of commemoration events. At 5 pm CET the participants, including the officials listed above, will lay down candles to pay tribute to the victims. It will be televised live on Polish TV, but I've no idea if it will be available online or in any other foreign TV channel, most probably on stations like CNN or BBC World.