In 2014, you have no chance of delivering a great conference talk if you don’t show real samples and code for at least half it, or even better live coding. It’s a way more innovative style of delivering a talk and the audience will appreciate you keepin’ it real as a coder. But Powerpoint and Keynote don’t allow embedding live code and iframes with your web apps, so wouldn’t it be neat to be able to do presentations in the browser? Sure, you might lose the ability to go full screen properly (i.e. with a presenter screen), but who needs presenter notes anyway.