Exactly. Remember when you had to pay $0.10 per text, or an extra $30 a month for unlimited texting. Then some company came along (I forget which one, but it was definitely named after a fruit), and introduced a messaging system that pulled the plug on that money grab? When everyone went to using that messaging system, the not AT&T carriers had to stop charging for texts because everyone was switching to Ma Bell for free messaging. This, in turn, force AT&T to stop charging for texts.
So, while I would love a better experience texting to a handful of Android using friends, I do not want to give the carriers a chance to go back to charging me by the message. I am pretty sure they would if they thought for a second they could get away with it.