CM's Bornakk and Nethaera give us a little something about the Wrath of the Lich King expansion and I figured they are probably stuff you guys would like to know. Bornakk tells us something about the 5 man dungeons while Nethaera clarifies how Death Knight creation and server transfers are going to work.
WotLK 5 man Dungeons
We are currently planning to keep the 5 person dungeons in Wrath of the Lich King fairly short in length, but with a boost to their overall epicness - the preview we have of The Nexus is a great example of this.
The more vast and sprawling dungeons will be found in the raid dungeons which more players will be able to experience with the changes to the setup. Source
Death Knight Creation and Server Transfer
An online poster in the official forums wrote this:
Bornak (I think) clarified that if a server is not yet open to transfers, then you need a level 55 on that server to create a Death Knight. Once it's open to transfers, though, it's fair game.
Nethaera replied:
This is correct. At this point in time, we don't have any further limitations on the creation. As always, I like to give a caveat that this could change if we feel it's necessary.
taken from here
It's good to hear that the 5 man dungeons of the next expansion won't.be too long. It's not that fun if a dungeon takes so long to finish. Dungeon length sometimes factors into whether or not someone can do the dungeon. Many times, I've been turned off by Botanica runs since it's pretty long.