That certainly is what this patent application filed by EADS , which shows a modified wing-fuselage fairing that is supposed to reduce drag from the installation of a larger engine, seems to indicate.

The problem would seem to be directly associated with the installation of the Pratt & Whitney Geared Turbofan (GTF) which has a significantly higher bypass ratio, and fan size, as compared to the engine currently used on the A-320 series.

The new fairing is the bottom of both pics.

Basically, it appears to be a sort of area ruling which accommodates the changes in air flow from a larger nacelle.