Yes, it’s true. You can harness the power of Flash to extend Bridge CS3 to build your own features. I just uploaded an example of this to the Bridge section on the Adobe Exchange website.
Once loaded into the Bridge startup scripts folder, the BridgeExportToJPEG extension will demonstrate a Flash UI panel in Bridge that is functional in driving Bridge to create JPEGs and manipulate XMP metadata. All the thumbnails that are created in Bridge are JPEG based, so it is possible to export these thumbnails as JPEGs – for example if you want to create a JPEG catalog or quickly send JPEGs of your RAW files. I’ve also included the FLA file for tweaking. It’s all available under a BSD license.