Buried amid all of the hubbub of WildStar’s free-to-play launch is the news that the game is no longer region-locked (although it still does not support cross-region play). Players can now select either the North American or European servers from the launcher regardless of where they live or what code is associated with that account.
“Characters / items / etc. will not communicate between regions, but you are free to play on either EU or NA no matter where you are from,” former CM Chilla explained on the forums. “You just need to change the region by clicking the cog on the launcher and swapping it.”
Massively OP has personally tested this and can attest that it does indeed work.
Source: Official forums