No God but Strings
...in string theory, the equivalence principle is a derived fact.
Joe Polchinski, writing in String Theory, volume I, page 115:
Because of the force from dilaton exchange, there is no equivalence principle, and so no way to single out a preferred metric.
String theory, supergravity and even quintessence, for example, seem to violate the weak equivalence principle because they contain many light scalar fields with long Compton wavelengths. These fields should generate fifth forces and variation of the fundamental constants. There are a number of mechanisms that have been suggested by physicists to reduce these violations of the equivalence principle to below observable levels.
There seems to be a contrary view.