Ofcourse the Text Messaging mannerism has contributed. & it's not just about saving typing space & efforts. I don't find this atrocious, but definitely adolescent. Like Raghu keeps repeating in Roadies' auditions - Wannabes, at-least at the inception of this behavior. Also, i observe here that it's an addiction, as people into it are not likely to return back to normalcy easily. I haven't found any application that specifically dudi-fies a simple sentence into a handy array of small & capital letters, but i assume there should be some, like this. In my research work prior to this post, i also could not manage to find any connotation of diseases associated with this behavior (so i assume the onus is on us). Regardless of everything said & done, I personally find replacement of a/o/s/i with @/()/$/! very very innovative.
It's apt to associate Hip-Hop/Rap genre of music with this wannabe attitude. As an evidence, please allow me to quote this excerpt from How to Be Cool at Hip Hop page
Forget the basics of the english language: As with rapping, try to retrain your tongue to move left to right rather than the more natural feeling (and sounding) up and down as you form words. If you only use one side of your mouth for talking it will create the impression that you have been capped in the face, and street violence is the coolest aspect of hip hop. Also, occasionally omitting vowels from words and forgetting to include words like "and" and "the" will make you look less like you grew up in well-to-do areas, and make strangers assume you were raised by wild dogs in the backyard of your Russian parent's slum house. Hopefully some day you will learn to speak your native tongue again and be able to forgive your family for the years of rehabilitation and psychotherapy that are sure to be required for assisting your return to human society.
It's just a phase in most likelihood, that would (and should) pass over. But it's remarkable how modifiable we are. The power of peer pressure at it's driving best. I thank, abstractly, that Hindi has been spared. At the same time, i do appreciate the truth how boring life would be if people just walked in straight lines.
PS: I ain't taking pot-shots at anyone. Please accept my apologies for any blood shed.