SMS is modernizing, popularizing and globalizing English. Though it is said that SMS is ruining English Language, actually it is using an innovative English. All direct and indirect emotions and feelings of the sender reach to the receiver within few minutes. It a natural process, so we cannot say that it is mechanical and artificial. Grammar in SMS is creative - punctuation are used as words, letters are used as sentences and words stand for paragraphs.
SMS language might not be an ideal model for learning English, but people are using it without any fear. They do not fear to use it and they enjoy English without knowing it. This is the biggest advantage of SMS.