Hi,
It is correct that Norconsult Informasjonssystemer has a tool to import graphics and attributes from PDMS into MicroStation. We now also have a tool called ExportPDMS that can convert any DGN or DWG file to PDMS. This tool can also directly convert i-models (i.dgn files) to PDMS.
Regards
Bjørn Egil Jenssen