I think everyone is eligible for the rebate...doesn't matter what you own. If you buy it from an authorized dealer you get the rebate immediately, if not, you can mail in the rebate. Might be best to go in and get a great deal from a dealer - say $1000 out the door - and then mail in the rebate.
The $200 off is now. The prices on the sweetwater site reflect that. Then you fill out the rebate form for $150. I think you have to register the variax with line 6 and then they e-mail you the rebate through paypal...at least that's my understanding.
Your Variax purchase must complete the dreamrig. You have to have all 3 registered, and you have to fill out the rebate form and mail it to Line 6. Then they send rebate to you through paypal. www.line6.com/dreamrig/ for details and rebate instructions.