There will be no Sanctuary cities like Dalaran or Shattrath in Cataclysm as confirmed by Zarhym last month.
Quote Originally Posted by Zarhym
We don't have plans for a sanctuary city in the likes of Shattrath or Dalaran for Cataclysm. For the most part players will be working out of their current faction capitals to keep in the spirit of bringing life back to the old world Azeroth.

Taken from:
http://blue.mmo-champion.com/1/22418...s-in-cata.html