It is pretty cool, especially the new Haunted Burrow. A Casual Stroll to Mordor has a full guide. And, thanks to F2P, you don’t even need to be a subscriber to see it. The main events are all in lowbie-safe areas.
They keep adding more to the festivals each year. I like that. I also like when MMOs keep adding more little festivals. The long-run goal is for something special to be going on all the time.