There is a pretty strong theory going around, which people discussed both on this forum and on other websites, I even heard it being mentioned in a popular warcraft podcast yesterday, that Blizzard is on the verge of splitting. Ghostcrawler and Rob Pardo leaving apparently was because of their old special employment contracts ending and the new ones they were offered by Activision not being up to their standards. This coupled with many business and design disagreements with the board of directors of Activision-Blizzard apparently many of the core Blizzard employees are planning to leave over the course of the next few months. It might not be a surprise when soon Chris Metzen also leaves the ship, followed by Tom Chilton, Samwise Didier, Morhaime, Tigole and many other core members.
But where would that leave you?
Would you keep playing World of Warcraft designed by people who don't have the vision and experience of the 'real' Blizzard? Or would you as a customer follow along and rather support the games of the potential new company instead should Ghostcrawler, Rob Pardo, Chris Metzen and everyone else of the old team decide to start anew? Do you think WoW would have a future of quality gameplay without these people or would you put more trust in the core team instead?
Edit: There is obviously also the implication that by doing this they plan to boycot old Activision-Blizzard and might hope to see Warlords of Draenor being delayed until Q2 2015.