OK. I am really sorry but the fact that all of you are attacking a dialect like this is really annoying me. The purpose of language is to transfer information from one person to the other. As long as the receiving person easily understands this expression of knowledge then that use of language was a success. I admit and am proud that I use abbreviations and "1337 speech" when I am using AIM and other instant messaging tools. It saves time and these uses often gain connotations of their own. Some of you say that you can type normal sentences very quickly and so it wouldn't save you time. However this is ridiculous because using abbreviations reduces the time it takes to type by a percent so no matter how fast you can type now if you typed using abbreviations it would be even faster.
The origins of the dialect are irrelevant, the English language originated from both Germanic languages and the French. This does not mean that the Germans or the French have any especial call to say how English should be spoken. Languages change over time as the needs of society change them. The purpose of all the fancy punctuation and capitalization in English is so that the reader can better understand what the author is saying. However who really speaks in perfect sentences and with perfect grammar(except politicians and speech writers). The reason is because if what is spoken is misunderstood the listener can easily prompt the speaker to clarify what they said. The same goes for forums and to a greater extent instant messaging tools. The reader can easily ask the author to explain what they said which makes the importance of proper grammar and spelling less important than if it were, say in a book. In a book the reader has no ability to ask for clarification from the author so it is very important that the author is understandable. Not using proper grammar is not "abandoning English". Instead they are just using a different form of English no better or worse than the type you are using. The world "lol" might have originated to mean "laugh out loud" or whatever it did, but now it no longer strictly means this. Instead it has gained connotations created from its use.
You are all complaining about how horrible this is for the future. What effect will it really have? If people begin using abbreviations from the internet in day to day speech how will this adversely effect humanity? Just as you guys often admit this really sounds like elitism to me. You think that your way of doing something is inherently better and so that any change from your believed static perfect is perceived as a threat. Language is a continuously changing tool and in the end the "correct" way of speaking is defined by the speakers and not by some abstract principles preached upon them by others. If you went back just a couple thousands years you'd find true "old English" and chances are you wouldn't be able to understand it. It has its own alphabet and is so significantly different from English it is effectively a separate thing. Change in language is not something you should be afraid of, it is something you should welcome and embrace as a new and better way of expressing ourselves in a changing world. Really your attacks remind me of arguments long ago by the aristocracy of how icky the peasantry were and how terrible it would be if they were running things.
In the end the really important thing is only that you understand what the author is saying. If you cannot then either you are not sufficiently versed in their dialect or they really are being difficult to understand. If the former just try to gain a better grasp of the dialect through a third party or by asking the author. If the problem is the latter then just ask the author to be more clear. In some ways you all have a point in that if they author can't be understood then they fail. However your grouping all of internet speak including together and saying that they are all the same thing. You can use internet speak and still be totally coherent, just like you can use normal writing and be totally incoherent (like I'm sure some of this post is). Changing language improves it, it does not "butcher it".
In short there is nothing wrong with using internet speak as long as its understandable. The world is not going to end because people use abbreviations. Using abbreviations is not "abandoning English". If anything your failure to acknowledge changes in English is you abandoning English. Changes in a language does not mean your "butchering" it. Language is not static. Get over it.
http://camba.ucsd.edu/files/misc/ll/grammar_puss.htmlPS. To the person above me I doubt that American English will every become a separate language from Standard English because globalization and improved communication seems to be removing the barriers which led to the divergence of dialects causing them to form different languages.