I'm not overwhelmed by Lightroom's web gallery generation module - behind the scenes it's overcomplicated to customize, for instance to add a shopping cart link. But I was a bit overrun with work when Adobe Media Gallery was published and have only just got to look at it:

Photoshop Elements and Lightroom ship with a single SWF file containing the gallery program, which users can customize extensively using the authoring interface in those programs. These programs produce XML files that the SWF parses to style the gallery and determine its content.

Essentially Lightroom's Flash output is an interface to this AMG component, and there's nothing at all to prevent you from generating the XML from another program such as Portfolio or iView, and using that data to power the Adobe Media Gallery's Flash movie.

The attached VB code is my first attempt for iView. It regenerates the group.xml file, and you will need two iView Convert Images settings files, and a little confidence in hacking my code.

It's completely unsupported, but let me know if you try it.

Update - didn't realize that the script wasn't displaying correctly, so here it is: Adobe_gallery_maker.vbs