I've been enviously eyeing the events over at World of Warcraft for Halloween. However, it seems the adventurers of Tyria won't be left without a little candy:
Check Lion's Arch, Droknar's Forge, and the Tomb of the Primeval Kings for evidence of the temporal shift, and, perhaps, find clues to the causes in this cryptic poem:
When the moon rises high over Lion's Arch
And the wind moans through the most hollow of eves
Shutter your homes this holiday
Steer clear of the shadows
For on this night, they say,
A long-addled spirit returns from the grave
Pumpkin upon his head,
A wicked deed within his heart
A pint of witch's brew for all those who misbehave
Heed these words, all ye who dare enter here:
Bind your souls to the mortal realm
For the regent of madness draws near.
Come visit us! And if you're frightened, you can always bring your mummy.
They're also sponsoring a fan art Halloween contest, have the usual wallpaper fare, etc. I haven't had time to stumble online for the last week or so, but will definately poke my head in to see the sights.
BONUS POINTS: Ok, I poked my head in. It's really very cool. Merchants have been transformed, there's enormous ghastly things coming from the ground and deathly heralds for someone called the Mad King, who seems to really want you to buy some absinthe or witches brew (new collectors). I only saw changes in Lion's Arch and Droknar's ... although I don't remember the spirits at the Temple Of Ages willing to accept donations before either. Not sure what's that about.
Well done, ArenaNet.