We need to emphasis here that these changes are only possible, and are by no means set in stone. Don't get upset if you don't see in them in patch 5.2; or ever. You haven't been promised anything.
That said, it's neat to see what Blizzard is thinking for the next patch. Zarhym's tweet as follows:
.@iizeppii Removing main-hand/off-hand Xmog restrictions maybe by 5.2. Also allowing Xmog of weaps w/ similar anims (2H axe/2H sword, etc).- Zarhym (@CM_Zarhym) December 3, 2012