Will Mobile be the End of Facebook?

Molly Wood of CNET has an interesting perscpective on the future of Facebook - 

If Facebook dies (and it might), its killer will be born mobile

Have kids and teenagers abandoned the computer and now only use the smartphone and tablet as their only means to connect online? What do you think StartCoders? Do you spend most of your time web surfing on your iPhone, Android or tablet rather than turning on the computer?