There are a couple of ways we could go about this- we could just send our emails to the magazine's editorial email address, or we can send them with "attention" to one of the S&V editors in particular. I recommend David Ranada, because I think he's their resident Star Wars nut, so if you choose to send your email to Mr. Ranada, make sure you include "attention: David Ranada" in the subject line (or on the envelope). If you don't want to direct the email to David, then just send it to "Editor".
Also - PLEASE REMEMBER TO INCLUDE YOUR NAME, ADDRESS AND TELEPHONE NUMBER in your letter or email. They need that info for verification, and if they print your letter, they will only include your name and town.
For reference, their website is:
http://www.soundandvisionmag.com/
Here's the contact info:
soundandvision@hfmus.com
Sound and Vision
1633 Broadway
New York, NY 10019
USA
Attention: (Editor, -or- David Ranada)
Again, thanks for your help everyone!

EDIT: For those of you who would like to reference a past S&V article in their letter, darkhelmet has gone to the trouble of compiling some links to past star wars-related articles:
Lucas interview by Carrie Fisher
John Lowry: Restorer of the Star Wars movies for the 2004 DVD release
SW: ESB Director Irvin Kershner Interview
Please keep in mind: This writing campaign is NOT about changing the September DVD releases but is about blasting Lucasfilm in the public arena for its shoddy, sub-standard presentation of the watershed original epic.