For pvp "Go Gnome or Stay Home" imo

Escape Artist + smaller size + able to play a DK with pink ponytails = OP

He is not asking about PvE (about the Spellcaster tanking.... BELF talent to which almost all bosses IG are immune anyway) or about the look (on the undeath).

He is asking which racial would be better for PvP.

Actually I just thought DK is the only class that will be available to ALL races and both factions, would be interesting to get some stats once WotLK is out for a while on the repartition of races for it.