I think it could replace it for me when Apple releases a Pro model that adds more processing power and RAM, a larger display (around 11-12"), limited USB device support (using apps and extensions to import files from a scanner, for example), better file management (perhaps with an iCloud Drive app), pressure sensitive display with better stylus support for drawing and design, and better keyboard support with perhaps a slim, Apple designed keyboard case. Obviously I would also need the software, such as more complete versions of Adobe CC, a more complete version of Coda, CodeKit on the iPad (although I could potentially get around that by compiling on the server), and split screen multitasking so that I can quickly and easily check against Safari while I code. But I'm still not sure about this as it's not going to be ideal. Perhaps for the design side of things, and especially the photography side of what I do, but for coding and maybe video editing, IDK. I wonder how long until we'll see Xcode for iPad, haha. Probably within 5 years. I mainly see the iPad as a starting point where I can get things going, and then finish up and polish on my Mac. Perhaps iOS and Mac OS will converge to the point where your iPad is in touch mode, and then docks into a keyboard case or is hooked up to a display and goes into mouse/Mac mode. That way you can easily get started, and then hook it into a huge screen with a desktop interface to finish up things faster and make them look great. With some kind of Thunderbolt interface you could even have external drives and video cards to help boost capacity and performance. But that's probably a ways off.