I ran across a post yesterday, and unfortunately, I can't remember where it was. That said, I did some research and found that the promotion applies to ALL 2+ GB packages, and not only the 2GB package.
Verizon to double data amounts for 4G smartphones (Updated!) | Android Atlas - CNET Reviews
Verizon to double data amounts for 4G smartphones (Updated!) | Android Atlas - CNET Reviews
For example, someone who subscribes to the 2GB for $30 plan will receive 4GB instead. For $50 you can get 10GB instead of 5GB, and for $80 you can get 20GB instead of 10GB per month.