And Richard Sterling, emeritus executive director of the National Writing Project, is, like, totally kewl with that:
“I think in the future, capitalization will disappear,” said Professor Sterling, who teaches at the University of California, Berkeley. In fact, he said, when his teenage son asked what the presence of the capital letter added to what the period at the end of the sentence signified, he had no answer.
"Informal Style of Electronic Messages Is Showing Up in Schoolwork, Study Finds," New York Times, April 25, 2008.
The study was conducted in 2007; it's based on eight focus groups and a survey of "700 nationally representative children, ages 12 to 17, and their parents."