I've always heard "wizzy-wig". As to Eos, I've never heard it spoken actually, but I've always heard it in my head with long "e" and "os" pronounced the same way as in "DOS" or "albatross".
EE-os - E like see and os like toast was the way I heard the ETC rep pronounce it when touring ETC-Middleton. I've also heard it's the exact same pronunciation as the Volkswagon Car, EOS.
From what I've heard at the local roadhouse (where they have an Eos as the house board), they pronounce it "Ee-ahs", the same as the Greek goddess. (Source: Eos: Definition from Answers.com, the pronunciation key)
WYSIWYG. I've always heard people in the computer world refer to the concept as Wiz-E-Wig. The tech theater world in regard to the software application seems to be very inconsistent on how to pronounce it. I go with the computer people.
Eos. I believe the original Greek would have been pronounced with a short e and short o sounds sort of like eh-aw-s I believe ETC has gone with the Americanized pronunciation which is E-ohs. That's a Long E sound followed by "ohs" as in dose, diagnose, comatose, morose
SteveTerry, Sclaussen, Lafalot, Jmabray... can someone give us an official answer?
I believe Aussies are required by law to pronounce both terms completely differently from anything posted so far in this thread.