I'll add in an option to install an older version of LWLGL in the next client update that should hopefully fix this.
Actually, could you install http://sourceforge.net/projects/java-game-lib/files/Official Releases/LWJGL 2.8.5/ ? If you need more specific instructions than that, tell me.
Get the lwjgl.jar, jwjgl_util.jar, jinput.jar files and put it into bin/, and then in the natives/ folder for Mac OS X, copy the .dynalib files and such and put them into bin/native