You can read greek and cyrillic, it just has to be unicode.
I wrote up something in M$ word using the fonts/keyboard layout that they use in greece (old bitmap ones..yuck

). This was in OS9 (or classic for that matter).
I think if you just save it OS X might *not* be able to read the encodings. I saved the test document as a unicode document, and opened it in TextEdit and lo and behold I saw what I had written.
OS X can recognize greek, it just cant reproduce it due to the lack of fonts (well there are only one or 2 greek enabled fonts in OS X but since the fonts are window style ones any windows greek font will work in OS X) and the lack of a keyboard layout.
There exists a "symbol" keyboard layout BUT it doesnt do accented chars and it is not a typical greek keyboard layout. It emulated the symbol font layout.
Admiral