WoW Insider is now reporting some transmogging differences that have come up on the Alpha servers for Warlords of Draenor. None of these changes have been officially released, so take them with a grain of salt, but as of now –
Axes, Swords, and Maces can be transmogged to and from Polearms. Staves can also now be transmogged to Polearms and back. Just to simplify the options –
Axes <=> Polearms
Swords <=> Polearms
Staves <=> Polearms
Maces <=> Polearms
Right now it seems like the biggest beneficiaries to this are going to be warriors and druids – but it’s definitely worth keeping an eye out to see about other possibilities opening up as well.