Interesting history. Are you sure that "kentron" is right? The meaning doesn't seem to follow.
The Theatre one is good though. But I think from what phranque was saying, the original "theater" in this thread was a typo.
However Latin is Latin. Greek is Greek. We haven't changed it, and still called it Latin.
We have a lot of French in our language, among others, because of the number of times people have tried, and failed, to invade us. Some phrases, "faux pas", "téte á téte", and my favourite, "ménage á trois", I'm sure you'll be familliar with.
I think the point is, some spellings differ, and some meanings too, take "pavement", in the US that's a road I believe. Whoever decided to change the language should have called it American, as the English are no longer responsible for it.
But then again.....can we say "Mayflower".....? ;)