According to Wikipedia, Apple has not opened the standard or the protocol although Steve Jobs said that they will open it, more here. A similar case seems to go with iMessages. I cannot totally trust the sources so how can I contact my friends that has no Mac products such as iPod touch, iPad 2, iPhone 4, iPhones 4S or Mackbook with things such as Facetime or iMessages?

Motivation for the question

I think Facetime and iMessages are pretty cool innovations but before switching to them, I want to make sure they are not just private closed groups -- it is a bit annoying to have just discussion with "Mac -guys" -way. I currently use Google voice but I feel Mac -style communication much easier particularly with iPad (my friend bought it to me for reading books but I am now finding the above apps quite useful).