Even if public opinion dislikes texting language, it has become a part of culture. It is an important part of how people are talking to each other today, especially the young who are ones being taught in school typically. While texting language should generally not be adopted as academic, we can still teach students about its cultural significance.
Cell phones should be banned from classrooms. They distract not only the students, but the teachers as well. Students are at school to learn. Plus when students text during class, they can easily cheat on tests. And people get in the habit of using short text in place of sentences while writing, or can't even spell the word they're texting.
About the only way that texting comes close to beneficial in schools is improvements in teacher-student relationships, as texting speak can narrow the generation gap between teacher and student, and increase the teacher's popularity. However, there are more and better ways to do this by using text speak. Using text language is - from a school teacher's point of view; I'm taking off my linguistics hat for a moment - sloppy as the student is not required to conform to orthographic conventions or to morphosyntactic rules that improve his or her writing. That contradicts one of the main purposes of schools, which is to promote literacy.
Texting languages should be simply limited to just phones and computers. The education system is already having issues with many students as it is. Texting promotes bad spelling which will affect their careers later in the future. It's an easy way to abbreviate on phones because it does take some time to type on a phone. But writing it out promotes bad practice.