On the one hand, everything I've read about how Cuba is organized internally makes me incredibly optimistic about the resiliency of their socialist politics. I think it's possible that Cuba might see some kind of sweeping reform movement at some point, but it will be more in the realm of China or Vietnam's reforms where the communists yield to some social democratic policies in order to try and curry favor with the US but retain political power rather than a full on color revolution.
(edit: in fact a certain number of reforms like that have already happened throughout Cuba's modern history)
On the other, people in 1988 thought that the USSR would last a hundred more years.