Here is a short report of my trip to Cayo Largo on January 12th 2012.
I booked the one day tour at Havana Park Central hotel. The total cost was 166 US$ (included airport transfer, flights, island and boat tour + food and drinks).
I was crossing my fingers to fly an An-26 but the morning flight was ATR-42 operated. I asked at the airport desk if it was possible to fly an An-26, they gave me two phone numbers (2030686 + 2030668).
The flight from Havana to Cayo Largo was 35 minutes.
In the morning, we visited the Marina and boarded the boat for a tour to Iguana islands, some nice places and arrived at Sirena beach at +/- 1 PM. There, we had food and drink. The guide told us to be back at the bar at 5 PM to go back to the airport for the flight back to Havana.
I asked him if it was possible to call the airport and know wich aircraft will operate the evening flight. I told him I wanted to fly an An-26 and was ready to buy a new ticket, even to Varadero (from where I could take a taxi back to Havana).
He introduced me to n old man who was a former An-26 pilot. That man told me there were two flight to Havana this day (my flight at 06:30 PM with an ATR and an other one at 06:20 PM with an An-26).
As soon as we get back at the airport, I asked the ground staff is it was possible to change my flight with the An-26 one. I was very lucky because there was one seat avaible on the An-26 and they gave me a new boarding car. I didn't pay any fee for that!
So, if you want to make that flight, call one of these numbers. The An-26 are still flying!
Here is the video