The race change feature is now available. You can’t create any of the new race/class combinations in Cataclysm, but you can at least change race.
I have already written a detailed head to head analysis of all races, from a tanking perspective.
Update March 2010: expertise only has avoidance value outside of ICC raids, so don’t worry about it.
What is missing, though: some of the new calculations on the avoidance value of expertise, which I’d discovered more recently. Based on that fine maths work, let’s go with 1 expertise rating = 0.7 dodge rating.
Human: 3 expertise skill = is 24.6 rating, so ~17.2 dodge = ~0.38% dodge before DR.
Dwarf or Orc: 5 expertise skill = 41 rating, so 28.7 dodge = ~0.68% dodge before DR.
Night Elf has flat 2% avoidance with no diminishing returns.
So Nelfs remain the best tank class… if you are happy with how they look, if you disregard the value of the mobility racials in humans, threat from expertise, and so on, as I discuss in the tank races post.
Personally, I’m staying Tauren because they look awesome.
Source: combat ratings, 45.250 dodge rating = 1% dodge.
Thanks to Kenshi who asked me if the night elf racial is worth it, if you’re currently human.