Thomas Holloway has posted a useful review of "dependency theory" and its variant, "the development of underdevelopment," the radical paradigm popular for interpreting Latin American problems in the 1960s and 70s. I think his main point is right: "dependency" theory was abandoned not because it was false, but because the praxis it implied led to massive defeats. When reality is so horrible (dirty wars and death camps included), but seems immutable, some people just try to learn to live with it and focus energies on policies that do seem realizable -- meaning, in Latin America, cooperating with the hegemon instead of opposing it.
And yet, Cuba has continued to resist re-absorption into the system, and a whole string of countries in South America (Venezuela, Brazil, Uruguay, Argentina, Chile and, more tentatively, their other neighbors) are working to redefine the relationship with the U.S. and other capitalist powers. "Neo-liberalism" doesn't explain these developments; "dependency" does better, but its Dos Santos-Frank-Cardoso expressions were pre-globalization (and pre-Porto Alegre, etc.), so need to be updated. What seems to be emerging is a post-dependency theory that does not yet have a name.