Since Blizzard has tuned Wrath raids to both 10 and 25 person versions, what's stopping them from rounding it out to a full 40. Perhaps they could even go for more. Many are already complaining that Naxx is too easy. They're looking for a real challenge. I don't know if Blizzard is open to the possibility of tuning up the dungeons, but we've seen evidence that the developers do listen to player feedback.
Would you want to go toe-to-toe with Arthus along side 39 of your best friends? Tell us what you think: