Superb! This really opens up a huge discussion and is very interesting. We are a small-medium sized company, so I don't think I will go with different domains, although I own them. I have redirected them for now.
I have gone into Google Webmasters and changed my preference from US to 'unlisted.' This might help and give it that international understanding. Not sure.
I may very well set up a UK homepage, an AU one, and perhaps South Africa or Canadian one. But, that will be in the future. I just don't want to lose the links I already have. It seems that getting links from these countries to your homepage would help saying to Google, "Hey, this is an international site in English and is appealing to all of these countries." It may not make me #1 in the SERPS, but it cannot hurt.
Thanks again!
Thomas