I've played an Undead through the new stuff up to Arathi, so I was definitely thinking about doing Kalimdor this time. I have the classes narrowed down to Mage, Warlock, Shaman, or Druid. Never leveled any of these.Gnomes get to see the aftermath of trying to get Gnomer back which is pretty cool. Similarly, trolls get the new Echo Isles stuff which is also cool.
I don't think anything has changed quite as much as the Forsaken Tirisfal -> Silverpine -> Hillsbrad route, though. Stonetalon is well worth checking out as either faction (and, in fact, both factions), so you could do a troll Durotar -> Azshara -> Ashenvale -> Stonetalon, and that would be pretty fun.
For humans, Elwynn is pretty much identical but Westfall is a proper sequel to how the zone used to be. It's nice to see. Same for night elves and Teldrassil -> Darkshore. Same then sequel.
Are the Goblins not any fun?