I ran last year's with an OMM Last Drop and a front chest pouch - in retrospect far too much storage and it only encouraged me to pack badly. Not running it this year, but now using a Nathan Vaporwrap for ultras - can highly recommend it. The Ultimate Direction Signature Series are fab too, depends on whether you want a bladder or bottles, I guess - I tried both and thought the Nathan fit me better.
I had a touch of hypothermia on The Wall - got into the last checkpoint, realised I was really cold and couldn't stop chattering teeth, also felt quite confused. Luckily they had a space heater so I ate something, stuck myself in front of it for a while and stuck on a thicker top for the last bit. Gave me a fright, and probably the biggest wake-up I've had in terms of looking after yourself.
The Kamleika tops are great - I've got a jacket and it just plain does the job. Not the lightest or smallest, but if I wanted the surety of knowing I'd be weatherproof that's what I'd take.
I picked up an Inov-8 thin quilted pull-on (Thermoshell?) over the summer - I've used it a bit, though I think it comes into it's own in the proper cold - very impressed with it.