OK, finally there is a way how to read INSPIRE GML 3.2.1 format in ArcGIS. You need to use Data Interoperability extension with the proper schema definition (xsd) which is available on the link mentioned above. INSPIRE uses its own schema description, therefore you will not by lucky with the standard ones. With regards to my previous note - at ArcGIS 10 it is possible to read GML 3.2.1, not write to.