The QlikView I/O operators can be used to read and write QVX and QVD files.
The Qlikview QVX operators are a new approach to a common operator that can read/write from different data sources such as Google big data, Workday, Teradata. These operators use the connector to configure themselves to the desired data source. To use this operator you first need to install the Expressor extension for each data source. The extensions will be released in the future. These extensions are also compatible with QlikView. These extensions/operators are a first example of how Expressor and QlikView code bases will be merged.
QVX in the name is a bit confusing indicating that there is a common underlying approach between the QlikView and QlikView QVX operators But does not imply that these operators provide duplicate functionality.
The What's New topic in the doc should have some more information.