I also use Calibre but not effectively with the edge (with a Kobo).

I am very interested in integrating the edge as a reader device within Calibre rather than just a mass storage device with the rigamarole needed to add books to edge's library.

Are you only doing the android end of the transaction?

If you are also working the Calibre end, is it possible to access both the internal mem as well as the SDcard seperately (like with the Kobo)?

I was also wondering about using the Calibre content server as a live feed for the edge, I don't have a library set up well enough to experiment with yet.

Anyway I will be very interested in what you and others can do.
SeeYa. FJH...