Collin Laverty at the Center for Democracy in the Americas has a great (and lengthy) analysis of Cuban economic reforms and optimal U.S. responses: Cuba's New Resolve: Economic Reform and its Implications for U.S. Policy. It is a highly detailed (including 127 endnotes) and quite balanced analysis of why the reforms are occurring, how likely it is they will last, and how Cubans perceive them. Their main conclusion is that the reforms are halting, imperfect, and difficult, but are here to stay.
The following is a great way to sum up how U.S. policy toward Cuba should be formed.
We believe the right way for the United States to assess the reforms is to ask whether they will enable Cubans to lead more prosperous lives and then determine how our country can best support this process. Economic stability in Cuba would allow its citizens to better share in civil society and in participatory politics (p. 60).
For those who support continuing the embargo, Cubans becoming better off right now is actually viewed as bad--we've been trying very hard for decades to keep them impoverished. If they become more affluent, this argument goes, they will support the dictatorship more. That is, of course, the exact opposite of what the U.S. argues for every other country moving away from Communism.