Our popular PvE specs
table is showing some very interesting changes since the introduction of patch 5.4. In particular, Destruction Warlocks now dominate the top 5% of raiding warlocks. They have grown over 100% since patch 5.4 at the demise of the Demonologists.
Other specs have changed as well - combat and subtelty rogues are growing with assassination dropping, frost continues to grow for mages (with arcane not far behind), survival has grown to equal beast mastery as the hunter spec of choice and frost DK's grow at the expense of unholy.
Protection warriors have grown in the tank ranks and restoration shaman and druids have also seen an increase in popularity.