As long as G. Lucas continues pronouncing Dough-koo, Geo-Gnaw-sis, Nay-boo, Hoth (rhymes with Both), Han (rhymes with Ran), and lightsaber (rhymes with lazer sword) despite what he directs his characters to say on screen, I don't think we have to worry much about it.
I like AT-AT though, for the record.
Lucas probably refers to them as "iron dinosaurs".