If I'm reading this correctly, then we're stuck with the lava appearance of doomhammer in our offhand. If this is correct, then this is an incredibly dumb decision that will ruin a lot of transmogs. I hope this gets reverted.
EDIT: "The weapons formed by your elemental powers will behave like normal weapons. You will be able to transmog over them."
Updated the title of the thread to reflect Lewor's edit. - Blithe