Interesting stuff.
I have some mixed feelings on it as usual. I don't think Blizz should be pumping out another XP just yet, as there is still alot of room for additions with the world as it is. Alot of players are still anticipating Zul'Aman, Uldum, the Azshara Crater BG, etc. Not everyone powerlevels as many toons to 70 as possible.
I did expect Northrend to be the next location though. That was inevitable and a good call. Most things I hear about the new continent are good. The Inscription profession sounds OK. Not as cool as JC, but could have some potential.
I'm not crazy about the Death Knight though. When Blizz first announced Hero Classes, they sounded awesome! Similar to D&D's Prestige Classes. Lets say I want to choose the Marksman Hero Class, open to Hunters and Rogues, I would level from 70-80 or 75-80 as a Marksman, gaining access to their abilities. This Death Knight smells of Jedi from SWG. One Hero Class (as opposed to at least two), being race restricted, and starting at high level, doesn't sound like the wisest thing to me.
Just my initial thoughts and 2 copper worth.