Bridge for QGIS
GeoCat does currently not provide a bridge extension for QGIS. However there are alternatives.
Publish (meta)data from QGIS to GeoServer
Boundless offers a QGis extension to publish layers from QGIS into Geoserver (http://qgis.boundlessgeo.com/opengeo/). Using a GeoNetwork harvester one can extract metadata from a Geoserver CSW endpoint. See this to set up your favourite metadata template in Geoserver (http://docs.geoserver.org/latest/en/user/extensions/csw/tutorial.html).
Share ArcGIS styling with QGIS
SLD's created by GeoCat Bridge can be used in QGIS (enabling the transfer of ArcGIS styling from ArcGIS to QGis).