The MFnWeightGeometryFilter class that was previously only in Python API 1.0, has now been added to Python API 2.0.
Two methods, getIndexMapper() and getEnvelopeWeights(), have been added to MFnGeometryFilter.
MStatus MFnGeometryFilter::getIndexMapper(unsigned int index, MIndexMapper& indexMapper) const MStatus MFnWeightGeometryFilter::getEnvelopeWeights(unsigned int multiIndex, MFloatArray &weights) const
getIndexMapper() gets the deformer's indexMapper, which defines the subset on which the deformer operates.
getEnvelopeWeights() gets the weights the deformer uses at the specified plug index.
The -minimumSize option has been added to the lattice command. This option can only be used with the objectCentered option, and can be used to avoid creating a lattice with a side of length 0.0.