The problem I see is that many people think proper grammar is boring and not very important so they would rather use u instead of you or 2 instead of two, to or too in every situation, and with everyone or try to learn and use slang first without realizing that could be offensive if you don't know when it's ok to use it. In my opinion that kind of thinking is what threatens standard language to some extend.

On the other hand I think sms language is ok IF you know when and where to use it. I use words and abreviations like thnx, ttyl, brb, jk, etc. when I chat or sms my friends but I would never use that kind of language to answer a question here on italki because I know it wouldn't be the best for people who are learning and will take your answers seriously.

I dont think its a threat in anyway to standard language. Any educated person knows the difference.
I think everyone uses some slang of sorts, especially among friends. From my point of view, its not a case of grammar being boring. But if its all very casual chat, whats the need for formalities?

Only thing i agree, its probably not helpful to people learning english. Provided they know its slang.

I agree with Mine and Harre, just want to add that in the Arabic language case, things are more dangerously advanced because the infinite use of loanwords from other languages (actual subject of many academic works ,and its impact on social classes), the phenomenon begins late 60's to 70's for some countries.
the use of latin alfabet to write words in dialectal local arabic and in frensh or english in the same SMS
and the new tendency to substitute sounds that couldn't be written in latin by Numbers, (eg: 9alb, 7obb,) is like to substitute "J" in spanish by "5" to italian speakers, the non spoken arabic letters in latin are 6 so imagine the confusion..
PS : is it the same thing for the other languages like mandarin, russia,..

I'm not sure if it's exactly the same but in Chinese you also have things like 88 (八八... ba ba) which sounds like "bye-bye" and is used in that way. There are many other phrases but I only know 88 and 521. 521 consists of the sounds "wu" 五 (5), "er" 二 (2) and "yi" 一 (1). However, with some creativity you can see that it means 我爱你 (I love you). "Wu" becomes "wo", "er" becomes "ai" and "yi" becomes "ni".
I don't think it has the same effect on people's literacy though because characters don't work like the alphabet. Here in the Netherlands it's possible to find errors everywhere, even in supposedly high-quality newspapers. When I look at how most kids these days write stuff, on MSN and Facebook/Myspace profiles for example, I'm really afraid that our education system has failed. A couple of weeks ago there was a teacher on national TV who couldn't even write a basic Dutch verb properly. What a sad world.

that's right it is kind of the "bad side of technology" personaly i write SMS in abreviated words and I use different symbol the result is when I m in class and I have to write standard language in arabic, french or english I make mistakes cause of this bad habbit ; thus it is really a serious problem that most of people never thing of it or never mind about it .

Harregarre makes some very good points, because as a teacher I have to constantly explain that SMS is not correct in formal essays at school, uni, work etc reports .

I think that different situations should use different express. when in a formal situation we should use formal English and we can use informal English in informal situation . No need to make ourselves tooo tired for this ,right? GOOD LUCK FOR EVERYONE.

i agree with you,also names of restraunts, shops are english names written in arabic letters
this damage our arabic language