Some WFS services that are to be supported do return coordinate lists in more than 2 dimensions. Yet geotools is not ready to handle them but we should still parse them as two dimensional.
For example <http://frameworkwfs.usgs.gov/framework/wfs/wfs.cgi?DATASTORE=Framework&SERVICE=WFS&VERSION=1.1.0&REQUEST=GetFeature&maxFeatures=3&typeName=hyd:HydroElementFLMD>
returns gml:posList srsDimension="4".
It ends up being that DirectPositionListTypeBinding does not takes into account the srsDimension attribute.