http://bugs.winehq.org/show_bug.cgi?id=24238
--- Comment #8 from Thomas Spear Speeddymon@gmail.com 2010-09-09 14:53:43 CDT --- If you have a windows install, login with wow in dx mode, and run the following in-game:
/script ChatFrame1:AddMessage(GetCVar("gxApi"));
That will print out the exact api that it's using (regardless of what is set in config.wtf). It'd be interesting to see when/where it uses DX11 (like maybe only when the new water effects are visible on screen?)