http://bugs.winehq.org/show_bug.cgi?id=24928
--- Comment #12 from James Christie james.aaron.christie@gmail.com 2010-11-05 20:55:21 CDT --- There is no dx10 mode in WoW. It only supports 9 and 11. OpenGL for the game only supports SM2.
Via dx9 and SM3 you can fully enable all graphics options in windows even if there are minor differences between 9 and 11 with them. That's where the issue lies.
Running wow with -d3d10 just reverts the game to directx 9 mode since d3d10 is not a valid renderer.