You're right Fidel's death will mean little in the short run, because he stepped down from power in 2006, giving Raul amble time to establish his power base. However, Raul said he is stepping down in 2018, and who follows is a bit of a mystery. Even if it is a reformist, the Cuban military still pretty much controls the Cuban economy. There is always the possibility for a Cuban Spring, and the security forces may not protect the government, but for that to happen I suspect they would have to see an opportunity for themselves and their families in the new Cuba.

Interesting article that came out prior to Fidel's passing, where Raul commented on Trump winning the election.

http://www.worldpropertyjournal.com/...trol-10150.php

Cuba's Raul Castro Reacts to Trump Election Victory

The 85-year-old Cuban leader has called out his military to show Trump, 70, and the world that Cuba can defend itself if the U.S. naively plans any kind of illegal military entry.

It's Cuba's first such exercise in three years.

As the military exercises wind down, at least 26 U.S.-based corporations have applied to President Barack Obama's administration for the maximum number of Individual business licenses to operate in Cuba.
The article explains the U.S. deal with Cuba in a fair amount detail, and Trump stated he wanted to redo the deal. Redoing the deal is not necessarily killing it, but one thing he wants is for all the political prisoners to be released. That seems fair enough, and maybe Raul will have more leeway to do that now that Fidel is out of the picture.

Raul did undo some Fidel Castro's communist mandates, and may undo now more. It is a waiting game to some extent, but one can always hope this is an opportunity for a better tomorrow for the people of Cuba.