As TnTkr suggests, it's more fuss than reality. Normal pump petrol has been allowed to contain up to 5% ethanol without labelling for years and years. E10 has been used in other markets for at least a decade.
No vehicle manufactured in the last 20yrs or so should have any real issue with E10, the industry has known about it and engineered systems accordingly.
Certainly there can be issues with older vehicles, but they aren't major in most cases. There can be problems with some copper based alloys (brasses) and some die-cast stuff, and some rubbers don't take kindly but any rubber fuel system component in the last 20yrs will be absolutely fine, the specific materials used are selected for resistance to the fuels in use.
Fuel consumption is hardly affected in my experience of using E10 on the Continent, you'd have to do a careful back-to-back test to measure anything much. Ethanol has about 2/3 the energy content per litre compared to typical gasoline (21MJ/L vs 32MJ/L taking density into account, 27MJ/kg vs 43MJ/kg), so in theory replacing 5% (additional) of the gasoline with ethanol will reduce the energy content of the mixture by less than 2%. That sort of fuel economy change is usually barely noticeable.
Ethanol does combine with water to some extent, but this can actually be a useful characteristic in that it "de-waters" the system. Water gets into the system anyway, and with no de-watering agents it can form water droplets which can cause localised corrosion effects. The ethanol will not make more water get into the fuel system in your car, it gets there anyway, best to purge it through.
There will be a "protected" grade of E5 (or less) for those vehicles which should not use E10.
The arguments for/against will go on for years, much like removing lead. World political aspects are another matter altogether.