Hallow's End has grown quite a bit this year. Adding to the old favorites of Innkeep Trick or Treating, PvP Smoke Bombing and Wickerman raids is the new Daily Quest to trigger the 5-man Headless Horseman event in the Scarlet Monastery graveyard wing. Considering this new mob drops Flying Broom Mounts, Evil Pumpkin Pets and Purple Jewelry, you can guess that he is going to be quite popular with the players.
New guides on defeating the Headless Horseman have sprung up around the Net. The fight doesn't seem too difficult for a group of L70s, but you can get an overview of all three phases and the loot table and WoW Wiki.
Also check out this excellent Hallow's End guide that covers all the activities for the holiday and lists the reputation gains and item rewards associated with each quest. Now put on your scary face and go get some Hallow's End goodies.
Looking for the new 2008 WoW Insider Hallow's End guide? You can find it right here.