Ok for starters I dont want SoE to go the route thats most expected, I dont want to see a 2 handed axe that is basically copy/paste Unending Axe of War, that would seriously dissapoint me.
Now I would suggest a really nice 1 hander , you can make it an axe if you wish

would like to see stats with proper allignment to the current expansion , make a decent delay between 2.5-4 secs and a good ratio for dmg spread, also would expect to see + to slashing and maybe another decent addition like the new Soulfire line. I havent had much time to think of a great effect but some that come to mind related to the class would be.
Enraged: 2.4ppm effect lasting 10-15sec
Increase Crit chance 15%
Increase DPS/Haste by 15-25
(something else)
Onsalaught Rage: 2.4ppm
On a successful attack this will trigger Onsalaught Rage on target
allowing 5 triggers to proc 500+ dmg on all targets in an encounter.
(similar to our Rampage line) - also being just a a dmg proc is kinda bland
so adding something else would be awesome.
I just kinda came up with these spur of the moment but depending on difficulty of risk vs reward its hard to come up with something I feel is fair. Maybe Archonix could explain the difficulty level in which this item will be to attain, like is it something ALL would have or is it something that would take weeks upon months of the hardest level of raiding?
Edit: PLEASE FOR THE LOVE OF GAMING DO NOT GIVE US + REGEN TO ANYTHING!