Text-to-Speech Cell Phone Feature

I am surprised that text-to-speech has not emerged as a cell phone feature. So that a synthesized voice would read your text message aloud. I'm not sure if it would make texting-while-driving worse or better (worse, because some people will listen to their texts who would not read them; better, because some people who would otherwise read them will instead just listen, which is an improvement, if still problematic).

Either way, though, that would only address the less scary half of texting-while-driving, the reading part (which is still scary enough).