ITT Visual provided an extension for ArcGIS 9.2 -- ENVI Reader for ArcGIS 9.2. It may still be available for download, but you will need to register a personal account with them.
From ArcGIS 9.3 forward, ESRI ArcGIS is able to read ENVI-IDL image format.
I'll verify if the 9.2 extension is still available for download and post back.