It’s obvious that globalized communications and popular culture will tend to homogenize local language varieties — but some varieties of English seem to be diverging more rapidly than ever.I like John Hayden's point too:
English is a tool, just like a piece of technology. Much of the world’s economy is tied up in English-speaking countries and for that reason, English is like a cell phone provider offering the best plan. But if the dollar continues to drop, the most viable option could shift.
Languages evolve via as-yet-unknown cognitive mechanisms. I suspect that "globalized communications and popular culture" will not change the way languages evolve. At best they will simply speed up the existing process.