seems the op didnt mention or overlooked the;
"As a thank you for current World of Warcraft subscribers, we guarantee that players with recurring (auto-renewing) subscriptions at the time of the price change will retain their current price for two years, as long as they remain in the same recurring subscription without interruption."
So as long as you are on dd etc thats another 2 years at the same price. As someone earlier stated its still behind inflation costs so it's not like they are just being greedy. However I will admit this does have one benefit to blizz in that it will encourage all current subscribers to maintain ther subscriptions untill after WoD hits so they can keep the lower pricing.