I was in the first wave of orders, but got this from Apple last night. Doesn't make sense .... I only ordered one! It even shows that clearly on my Order Status (which now says "Cancelled") 
Dear Apple Customer,
Thank you for your recent Apple order.
We appreciate your interest in iPad 2. There is a limited quantity per
customer for this product and your order has exceeded this limit. Your
order has therefore been cancelled and you will not be charged.
We apologize for any inconvenience caused.
If you have any questions regarding this order, please contact us at
applestoreinfo@apple.com.
Sincerely,
Apple Online Store Customer Support
Dear Apple Customer,
Thank you for your recent Apple order.
We appreciate your interest in iPad 2. There is a limited quantity per
customer for this product and your order has exceeded this limit. Your
order has therefore been cancelled and you will not be charged.
We apologize for any inconvenience caused.
If you have any questions regarding this order, please contact us at
applestoreinfo@apple.com.
Sincerely,
Apple Online Store Customer Support