what would it take to make a normal gas burning engine be able to run on Ethonal? is it even do-able?

It's always do-able given enough effort and money. The mods to the fuel system are fairly extensive in terms of seals and such to deal with the alcohol. It's been said that it adds up to $100 + if the engine is built that way at the factory. After market- I wouldn't even want to take a guess. Add to that it appears that the computers are not optomized for E85, but rather gas. So, while a flex fuel engine will burn E85, it won't get all the benefits of E85 possible.

i think we will see sooner than we think

fuel injectors
maf
possable fuel pump
press regulator
ecu from e85 truck (may or may not be needed)

Fuel lines and fuel rails, E85 detector and ECU is needed.

E85 tuning is my next project...