I have just read Angelika Kratzer's paper "Conditionals". In this paper Kratzer rejects the traditional account of the "if-then" construction in English as a two-place material implication operator, in favor of a new interpretation of "if" as a modal scope modifier.
It seems to me that this account might provide an alternative resolution to Hempel's raven paradox. It appears to me that this paradox arises precisely because of a confusion between quantifiers and material implication: the statement "all ravens are black" is taken to be equivalent to "for each x, if x is a raven, then x is black"; then by the contrapositive to "for each x, if x is not black, then x is not a raven". The paradox is that in this form, observing a green apple becomes evidence for the original claim about ravens.
I think Kratzer's account would have something to say about the first transformation, in which the quantifier is recast as an if-then form which is then interpreted as a material implication.
I am most interested in references to the literature, but I would also be glad to see a summary discussion.