As it appears now, if I were to buy the upgrade, it would be attached to my existing account. The only way I would feel good about this is if I could attach the HoT to my existing account and get a separate keycode for the GW2 account that I could set up as an alternate account.
Otherwise, I feel like I am being overcharged. ANET, please respond to this or come out with a cheaper, HoT only option that does not charge your loyal customers as must as new customers.