It appears that WOW players are starting to leave the game. Perhaps this is a direct result of Warhammer OL beta test, which garnered 200k+ user sign ups. Perhaps it is a direct result of Blizzard banning many suspected gold farmers. Personally I think WOW has lost steam and will not be the dominant MMO in the next 6 months to year.
WOW losing steam chart. Click on picture for the full size.