Mix equal parts of desire for change and fear of it, season with a large dollop of apathy and a pinch of nostalgia for the good old days of Soviet subsidies, and put it under the watch of a heavy police presence on the streets. That's Havana, on the eve of a momentous vote to elect Fidel Castro's replacement as Cuba's president, marking the official end of his nearly 50 years at the helm of the government and opening the doors to reforms by his more pragmatic brother, Raúl. Or maybe not.