The PC Era is dead, we are in the Post-PC Era or some call it the Pro-PC era. Intel played a role in the PC era and the X86 based processors. They are even used by Macintoshes now. But all of that could change.
Intel almost had a monopoly until IBM had Intel sign an agreement to have AMD make chips in case Intel could not meet up with IBM's demand for them. Even PC maker used Intel chips, and later on AMD made them cheaper and brought in low cost PC systems as a result. Then AMD made 64 bit processors and licensed it with Intel. The X64 processor was born, and so was multiple core processing and hyperthreading. The PC was no more, it had evolved into the UberPC and software has not quite caught up yet.
Apple used Motorola 68000 and later on with a deal with IBM and Motorola joined the PowerPC alliance with them. It was to challenge the Intel threat and make better processors. Apple had their PowerMacs and CHRP systems based on the PowerPC chip. In 2006 Apple went to Intel chips because IBM could not keep up with Apple's demand and favored the many video game consoles that used PowerPC chips like the XBox 360, Playstation 3, etc. Apple converted their Mac OS X operating system to Intel chips and then later on dropped PowerPC support.
All looked well for Intel, they even bought out a few companies like McAfee. It seemed that only AMD was their real threat and it was struggling to survive.
But the mobile device era came about, along with it came the ARM chips. The ARM design can be licensed and then the ARM chips can be modified and then made cheaply. Apple uses them in the iPhone, iPod, and iPad, Microsoft uses them in Windows 7 Phones and Windows RT tablets, and suddenly some Dotcom companies found out that ARM based Linux web servers in a cluster is cheaper than buying Intel based ones.
Apple makes the A5 chip based on ARM designs and outsourced the manufacturing to Samsung. The very company it is suing over Android devices that also use ARM chips. Apple has plans, you see, to switch their Macintosh series from Intel chips to ARM ones like the A5, and has bought out a chip making company. Learning from the failed IBM Motorola Apple alliance, Apple wants to make their own ARM based chips. This would be a move away from Intel and force users to buy all new apps yet again for ARM based Macintoshes and end support for Intel based Macintoshes. It would also end the Hackintosh era where people modify Non-Apple Intel based PC systems to run the Intel based Mac OS X. Apple would kill two birds with one stone there. Take the iOS/iPad technology and use it for the Macintosh series.
Microsoft of course has Windows RT and would counter with more Windows RT devices. It has the same GUI as Windows 8, but runs on ARM devices and does not run Intel legacy programs. But if Microsoft pushed it more, they could push Intel based Windows 8 devices and Windows 7 and under devices out of support and end of life.
AMD is licensing the ARM design and will be making ARM chips soon. They anticipate selling more ARM chips. There are many computers like the Raspberry PI that show an ARM based computer for less than $100 can be a good seller. ARM chips use less power, and use a smaller size, and run cooler than the Intel/AMD X86-X64 chips. In a culture that wants to fight climate change the ARM chips are very trendy.
Need I say Linux, AROS, HaikuOS, and other operating systems are being ported to ARM platforms? We might be seeing the start of the ARM Era.
The PC isn't really dead, it has evolved to the UberPC, the old PC standard is the one that is dead. The old PC standard of 32 bit only, Intel X86, Legacy Windows/DOS, single core processor, non-hyperthreading, 32 bit addressing (3.5 Gigabyte RAM limit), and legacy 16 bit mode are over. 64 bit processors are in with multiple cores, hyperthreading, legacy 32 bit mode, RAM over 4Gigabytes (64 bit addressing). The UberPC or PlusPC, whatever you want to call it is the next step in PC evolution.
But somehow with ARM, less is more. Less instructions, less power consumption, less space, less overhead, less expenses, and a lower price tag. Sure an ARM chip won't run at 3.5 Ghz, yet, but unless you are playing really detailed 3D video games it does not matter. ARM chips are being modded for more cores, more hyperthreading, and of course faster clock cycles, and a 64 bit mode. So we might be seeing ARM Macs, ARM PCs to go with our ARM mobile devices.
What will Intel do if companies start using ARM chips instead of Intel chips? Will it end up like Sun and the Sun SPARC chip and get bought out, will it end up like MIPS and get bought and sold? Intel's best bet is to support third party operating systems like Linux and show why Intel chips run Linux the best, Intel needs to modify low end chips like the Atom to compete with ARM chips. Intel has to, as matter of fact, change their business model and business plan.