The Maimi Cubans must be gutted that he didn't die on the job. Resigning in favour of his brother means the regime survives, even if (as I suspect) Fidel is on his last legs. Any celebrations will be rather empty - the Cuban exiles aren't going anywhere fast, and haven't really got anything to cheer about.
1 - 'Castro Legacy Holds Despite Resignation,' by John Rice, published by the Associated Press, 20th February, 2008. (http://ap.google.com/article/ALeqM5hASp3fdaeN4JMV2fOR1FnodIWA0QD8UTO03O0)