I think this smartphone will replace the PC discussion is going into the wrong direction. It is not about being able to open and edit a spreadsheet, not about executing a word processor, not even about the actual GUI of the OS or the available apps. FPG is right that this has nothing to do with the computing power of a smartphone.
FPG argues that hooking a keyboard and a bigger screen to your smartphone does all you need with a PC. It is true that the current user experience simply won't allow for this. The mobile OSes aren't well prepared for keyboard control, their GUIs don't scale at all with larger screens and their compute power and memory capacities will find limits at doing some of the more demanding stuff of a PC. This all could be fixed within some years maybe (not in the short term, so no worries here).
I think, from a user perspective, the question is: Why should I do this? As a user, I can always and forever (!) get a higher performing device, with better battery lifetime (due to the larger battery), better integrated (instead of carrying three items, phone, keyboard, screen, why not just one nice laptop?) and just designed for what it is meant for: Doing more demanding stuff on a larger screen with a dedicated OS and applications with a nice keyboard all in the right package for the specific need, be it a laptop, an All-in-One or a full desktop. They all have their reason for existence.
To put it differently: Why connect a lumpy phone on a keyboard and screen when you can have a better device integrating all this? It just doesn't make sense and it won't happen, since those dedicated devices will always be better at what they do, especially due to higher performance and, no, once and for all, there will never be a good enough in computing performance for PCs. Just won't happen - and that's very different to digital cameras.
