Yeah everyone has been talking about it and it is happening right infront of us without even realizing it. The whole idea of leaving computers behind and moving towards handheld devices was something nobody thought possible to happen in a such short time.
Pc are being replaced by another devices as the center of computing, especially smart phones and tablets. The phenomenon changed the way we work, play and communicate entirely. PC usages are declining going in the way of the vacuum tubes, vinyl records, CRT monitors, typewriters and tape walkman era, soon to join the jump would be magnetic harddisk which will be replaced by SSD.
I still remember back in 2005 when IBM made announcement to sell its computing business to LENOVO, the company who designed computers are moving away from it? Seemed illogical right? But IBMs genuises figured it back then itself that moving away from PC is the right move, well even maybe they have contributed to it directly or indirectly.
Battery Powered mobile computing ranging from smart-phones, tablets, digital sensors that can monitor your vital signs, calories burned and etc is spreading all over consumer market.
Trend in energy efficiency, going green has increased the speread in mobile computing (Koomey’s Law) – the amount of power needed to perform computing task will drop by half every one and a half year, somewhat like Moore’s Law 1965 , number of transistors on a microchip doubles every two years.
The miniaturization of electronics, increased performance and efficiency in handheld devices, by utilizing latest cutting edge technology, smaller circuitry and less energy consumption has been a key in current devices development.
The Introduction of Apple Iphone, the first widely spread & successful impletentation of touch screen handheld device and a mobile phone changed the landscape of mobile devices, then comes the introduction of ipad which successfully killed the idea behind netbooks, and created its very own userspace which is relatively new!
I just read couple days ago that Apple Sold 3mil ipads in 3 days, that is something not to be taken lightly, on developers standpoint this is the right time to move towards mobile application development.
What I am getting into is, people who are still in the PC era, its time to realize and move on with the current trend, if mobile computing is the forefront we all should take the necessary steps to move on as well 
Its an ongoing transformation that will have positive adverse effect for everyone, its just we either jump in the bandwagon or be left out.
