We currently have no plans to add a 40-player Guild wars platinum dungeon into Wrath of the Lich King. We fully anticipate making the 10 and 25-player dungeons and raids challenging as a part of their progression. You can say what you like about whether or not a 10-player dungeon is truly challenging if you wish, but they take coordination and require each player to play their role to their best ability to succeed. However we haven't ruled out the possibility of ever adding a 40 man raid in this expansion or the one after should we feel it's something we would like to do?