This year, Apple repeatedly referred to this age as the "post-PC" era, officially downgrading its Macs and MacBooks to the rank of "device", equal to the iPads, iPhones and iPods in terms of how important it is relaative to them. With the release of iCloud, no device will be required to be "subordinate" to another.
With the release of Mac OS X Lion, Apple also transferred a number of design principles from its touch-screen devices to Mac, including large numbers of gesture-based controls (notably, scrolling with the trackpad as you might scroll down on an iPad - the "other way" to normal). Launchpad, Apple's brand new app organiser, is effectively the iPhone/iPad UI, and it all seems very much designed with a touch screen in mind. It makes the announcement of touch-screen Macs, or iPads running full-fledged Mac OS X, a more feasible reality.
Microsoft is doing a very similar thing with Windows 8, somewhat controversially announcing that it will use the Metro UI from Windows Phones as its primary UI, with the traditional "desktop" reduced to just another one of the many apps.
The issue for debate, really, is: Is the world truly ready for these "post-PC" devices, or are these simply radical changes made "for the hell of it" by Apple and Microsoft to make their devices more user-friendly and singular?
In the case of OS X Lion, things like the reversed scrolling seem somewhat unweildly when applied for a trackpad, and would be much better suited to a MacBook/iMac with a touchscreen. Patents for such devices exist, but the devices themselves do not. In the case of Windows 8, a friend of mine installed the Developer Preview and told me that it was nigh-uncontrollable with a mouse, and once again would be better suited to a touch screen-based interface. Very few computers employ touchscreens, and it's quite possible none employ them in the smooth, multi-touch-capable way that Windows 8 seems to demand. It seems almost as if Apple and Microsoft's ambitions have made their software "outgrow" the hardware it has run on without incident for years - and in the case of Windows 8 in its current state, almost renders all previous PCs obsolete.
But what do you think?