IMO the most exciting news from BUILD today is Continuum. I had a hunch they were slowly moving in this direction with universal applications and the same OS everywhere, but I didn't think they'd make the full push in this direction. Instead of using whatever third party services to sync all of my files and web history and searches and email across devices, I can run single instances of all of my applications and files on one computer. This is the same thing Canonical is doing with Unity 8 for Ubuntu. It probably won't be pretty (or popular) for a while, but in my estimation this the start of a paradigm shift in computing. I'm really really excited to be able to have a pocket computer that I can plug into a monitor and keyboard, or a tv and gamepad, and have it adapt to the environment and be able to use all the exact same apps. You can have one smart device instead of a smartphone, laptop, desktop computer, work computer, and three game consoles (yeah, this is a little ways off, but this is a step towards that future). I'm excited.