New update! Apple just announced:

"Later next year, we will be adding support for RCS Universal Profile, the standard as currently published by the GSM Association. We believe RCS Universal Profile will offer a better interoperability experience when compared to SMS or MMS. This will work alongside iMessage, which will continue to be the best and most secure messaging experience for Apple users."

So this means the no iMessage yet. But at least better cross platform messaging from an iPhone. This would not have happened if it was not for Nothing's pressure. A marketing masterstroke from Nothing.