It's more likely to change the PC market than kill it off, I'd say. Smartphone sales recently exceeded PC sales for the first time, in great part because many of the things we have traditionally use PCs for require relatively little in terms of hardware. Texting, email, document review (and to some degree creation), audio/video playback, even video conferencing to some degree...all of these things can be done on an entry level android device. Some things such as word processing work much better with a traditional keyboard, but still places modest demand on hardware, so a workstation can do pretty much what a traditional PC can there as well. I agree that a reason for the PC to see continued life is that some users demand the security/privacy that means keeping data behind their own firewall, especially when outside of an office environment. I see the PC's future splitting into laptops (for remote use when computing power is required) and workstations, where the hardware demands are modest. Evolution, not extinction is my guess for the PCs future.