If you're into Ambisonics, do subscribe to the Sursound mailing list. It's an extremely useful - and sometimes very lively - forum for serious surround-sound discussion, not just on Ambisonics but on the whole topic of surround-sound in general.
The list was founded by Jim Rusby and Jeff Silberman.
You can join the list and manage your subscription by visiting the following address:
List Sursound is provided for both researchers and producers of multichannel audio as a place to exchange ideas. Manufacturers are welcome to join in- announcements of relevant products are acceptable, please use restraint. This list is oriented to professional and hobbyist alike. To see the collection of prior postings to the list, you can also visit the Sursound Archives.