It looks great ... it has optional water cooling if you want to use it with heat chamber or high speed / high temperatures ...
Here is summary by Sanjay from Ultimaker forum: http://umforum.ultimaker.com/index.php?/topic/1877-e3d-all-metal-hotend-for-ultimaker/page-3
Concerning water cooled and multi-nozzle hotends
Because there seems to be a bit of speculation/confusion surrounding this I am going to let the cat out of the bag.
We have on the way a small prototype run of a 4 nozzled, water cooled, bowden fed hotends.
We are calling this new hotend "Kraken" - A multi tentacled water borne monster!
The total footprint of the hotend is only 30*40mm in XY plane, the Z height from top to tip is under 40mm, and the 4 nozzles are arranged in a rectangle only 20mm*18mm apart. The weight without electronics looks to be around 110 grams, which is barely the weight of 2x E3Dv5 hotends. Each nozzle to have separate temperature control. Each nozzle can be individually levelled and adjusted in height to be planar with the bed in a very easy and quick way.Update:
The small size and weight despite 4 nozzles is due mainly to the high efficiency of water cooling, even with only a tiny amount of water flow and a small cooling channel we still have a massive excess of cooling capacity. The second reason is a new way of mounting/gripping bowden tubes which has all the convenience and grip of pneumatic push-fit couplers, but with significantly less bulk and weight.
We intend to keep the price reasonable, and below the price for buying the equivalent number of E3Dv5.
But to be clear - Kraken is not a replacement for the normal v5 hotend, which will remain our main product that suits most users. The Kraken is designed purely for multi-nozzle bowden feed applications. Futhermore it is not finished! We will be shipping the majority of our beta prototyping run to trusted testers. I expect problems to occur and tweaks to be necessary. I will start a separate thread once things are ready, and the final version of Kraken will be developed in a public/interactive manner so the community can input what it wants/needs so that we can give you guys what you want.
Kraken will be open-source when sold publicly.
Here is the new E3D mixing extruder preview:
Update 2 (24.5.2014.):
Sanjay released new v6 hotend: