New BD Fuel, photo stolen from:
I haven't seen or played with a pair in person yet but my guess at the basics having seen earlier prototypes, are:
Slightly lighter in weight than Fusion (no hammer on the Fuel so a given I suspect)
Better balance by ditching the hammer.
Assuming from the BD comments as a "more all around/better ice tool it will be delivered with the current Fusions "ice specific" optional pick. 2 degree drop in pick angle is going to climb like/will be closer to a Cobra than a Fusion. Numbers don't lie.
Lower profile spike than the Fusion (removable as is the Fusion's I'd assume).
Black oxide finish? No more loose head bolts and picks. (chrome plate was a rookie mistake)
All issues noted on the original Fusion @ its debut.
Retail is unknown but assume it will be comparable to a Fusion. No clue when they will be available to the public. Likely Fall of 2014 if they are presented at Winter 2014. Long wait if you need new/want tools this season. Nice on BD's part to give us all sneak preview at the 2013 Bozeman Ice fest.
The current Fusion, the tool the Fuel is based on in part
I've climbed with the Fusion a good bit and written about it several times. The Fusion isn't and wasn't intended to be a beginner's tool. The Nomic is very versatile/ A good many climbers rightfully though/hoped the Fusion would be as well. The "ice specific" pick has helped. But the Fusion is still a full on race car. Not the family sedan. If the design fits your needs, great. If not, better to look else where for a ice tool to make everything fun. If you throw/ envision a figure 4, I susepct you'll have all this sorted out aready. There are enough good tools out these days that you won't have to look far. I suspect the Fuel is a 2nd attempt with the original Fusion design/redesign to gain some of the Nomic's obvious market share.
I hope they have succeeded. Always good to have options!
Looking forward to trying a pair myself when they become available. Keep an eye out! There should be any number of good reviews coming from the sales samples BD is handing out right now.
Me? I really like the color combo ;-) And all this is just my best guess, reality and YMMV!