According to the knowers-of-all-things-Volt over at GM-Volt.com (which incidentally just got a very nice site redesign), the initial batch of first-model-year Chevrolet Volts won't be flex-fuel capable as initially planned. Says vehicle executive Tony Posawatz, "We are finalizing some of our options and the associated timing that goes with them. The E85 capable emission package will have its timing finalized soon... It will not be available for November 2010."
It will apparently take a full year or so to get flex-fuel capability built into the Volt's 1.4-liter four cylinder engine/generator package. Of course, none of this matters all that much if you plan to almost exclusively operate your extended-range electric vehicle using the electric motor and lithium ion batteries, eschewing as much reliance on fossil fuels as possible... but even that strategy won't be possible all of the time.
Interestingly, Tom Stephens, GM's vice chairman for global product development, said at the Renewable Fuels Association Conference in Florida, "GM is spending about $100 million a year adding flex-fuel capability to our vehicles," but it can't continue to make that investment without further support and intervention from the U.S. government. We'll leave it up to you to decide whether or not that would be a good or bad thing.