The early release for prePURCHASE and ofc the price hike is yet more indicative of Blizzards financial obligations to continue to turn a profit for their investors even with diminishing revenue streams (overall sub losses trends for the last few years).
They cannot from a marketing point of view over saturate the Blizz store with a new shiny pixel mount every 2-3 months anymore, and expect continued high levels of purchases from players willing to pony up the cash. Eventually even the die hard loyals will get fed up of yet another mount being shoved in their face each financial quarter.
So this financial quarters marketing gimmick is getting revenue from pre purchases of an expansion that has no confirmed release date and is not even in beta yet. In addition to the revenue they squeezed out from the Iron Skyreaver, which may not have sold as well as they had initially hoped. I wonder what it will be next quarter if WoD does not indeed ship before the end of June (almost a foregone conclusion at this point).