Well, you can't just dump it in there and expect it to work, the engine will run badly.
E85 requires more fuel delivery because Alcohol has 1/2 the BTUs of gas. The engine can also run more ignition timing.
So really, you need to tell the computer to deliver more fuel, and to bump the timing to take advantage of the greater Octane rating. More compression would be nice to take advantage of the higher octane, but is not required.
From what I've been reading is that there are two ways of getting more fuel to the cylinder, increase injector size and leave the durration the same, or change durration.
There are E85 kits out there. It sems to me that in their basic form, they fool the computer into delivering more fuel to the cylinder. Not sure about the timing.
http://www.change2e85.com/servlet/StoreFront
Corrosion should not be an issue. There were complaints when the nation took up the 10% Gasahol standard that fuel systems would corrode up, that was back in the bad old carb days. Since then, fuel systems have been designed to be immune to the affects of Alcohol in the fuel as it was assumed that at some point every owner would encounter E10 on a regular basis.