I believe they willl charge around $175 per home.  It will support most 2-way features "as-if it was the Sonos interface itself" at ISE they told CE Pro that they are trying to imitate the module as close as possible.

I know EV has a n API for Sonos which makes them uniquely positioned to offer the module.

I hope they do their iTunes module and do some sort of XBMC integration!