I have the same interest!
The issue I'm having is iMessages does not send/receive texts. If an iPhone user responds to my message but steps out of range of wifi, I won't see it on my laptop, because it came through as a text. It makes for a very inefficient workflow. (In addition, not everyone has an iPhone.) Thoughts?
Well, this thread is over a year old.
As for iMessage, it only applies to iOS users. Therefore there is no concern for non-iOS users. Also, being out of the range of wifi does not stop a message from being sent as an iMessage. There's this thing called cellular data, I'm certain you are aware of it. ;)