Texting is an emerging type of communication that has its own rules, but its use does not mean an end to correct grammar use in written English language.
Whenever a new literacy develops, whether it is the novel, the television script, or the blog, questions are always raised whether the new type of language use will lead to the demise of previous types of literacy. However, literacies do not emerge only to replace prior literacy practices. For example, the novel did not replace poetry, and the television did replace radio. Technologies do adapt and change when faced with competition, and the same is true of literacy, which is a type of linguistic technology. However, this change does not mean a complete abandonment of rules or principles which make that technology possible.
One concern about an emerging technology involves texting. Texting involves an abbreviation of words to the simplest form so that people can get information quickly. It still uses the traditional rules of grammar such as verb use, tenses, and parts of speech. Texting is not the same as regular written communication, that is true. But the specific differences involve spelling and use of periods, commas, and other punctuation marks. Text messages use words that can be understood in shorthand manner, such as text being spelled as txt. However, the abbreviation does not mean the original spelling of the word is lost or isn't used in other contexts. In terms of punctuation, when someone writes "I love you" without a period at the end, within a text or outside of a text message, the period is still implied.
Thus, even in a text message, the traditional rules of grammar are always implied. Just like in a poem which might play around with language and not use traditional punctuation to make its point, the text message does not create a new grammar or signal a break down in grammar. In fact, texting in itself has certain rules or commonplaces that people must adhere to in order for their communication to make sense. This standardized aspect of texting makes it a sub-language in itself, rather than a replacement language.
The underlying question of whether texting means the end of grammar involves a certain techno-phobia or a placement of traditional English grammar on a pedestal. It is politically similar to people who feel that Ebonics will lead to the end of English or the idea of "English First" in many states in the U.S. Language is evolving and changing over time--it isn't a static entity that needs to be protected. Not is English an endangered species under threat from various literacies. In fact, new forms of literacies tend to reinforce traditional language practices by making literacy in general more used and important in daily life.