This is the arena spec I'll be trying first.
http://ptr.wowhead.com/?talent#jfVhZMGezArcoczcudAoc
I chose acclimation instead of merciless combat for survivability purposes (also makes killing frost mages a bit easier), and also with the new DW build it's going to be a bit less bursty, but the damage output should be totally consistent. Also, rime is proccing off the offhand, and offhand dodges etc don't waste runes. There's a bunch of ridiculous shit behind this new DW spec.