The news that Apple is switching from IBM to Intel chips inside its machines could spell a period of confusion for consumers, some analysts are warning.
The move has had mixed reaction
The move, officially announced at the Apple Worldwide Developers Conference on Monday, could mean people hold off buying new Apple laptops.
Apple said it was making the move to x86 architecture chips because they offer more power and better efficiency.
The first Apple computers with Intel chips will be on the market next year.
That is likely to be the Mac Mini, with the entire product line switching by the end of 2007.
Applications will continue to work on both types of chip-sets for some years.
But Graham Barlow, editor of MacFormat magazine, said some people may not buy a new Apple machine knowing that a new processor was coming out next year.
"That must be the worry for Apple retailers. I think it's highly likely there will be some price drops to tempt people to buy the final stocks of PowerPC equipped Macs," he told the BBC News website.
One main motivation behind the switch is because IBM has not yet been able to produce versions of the G5 chip, used in Apple's desktop G5 machines, which are suitable for Apple laptops without overheating.
Intel is the world's largest semiconductor company. IBM and Motorola (now Freescale Semiconductor) have been providing PowerPC chips to Apple for more than a decade.
The announcement has come as a bolt out of the blue to many, and experts say it is one of the biggest transitions in the Mac market since the move from OS 9 to OS X operating systems.
Some analysts have suggested that the transition could further damage Apple's low 2.3% worldwide market share, while others say it is a logical decision.
Others worry that it is a big gamble for Apple because it might create consumer confusion, and could damage support from a loyal cohort of Mac users.
Gary Barnett, research director at technology analysts Ovum, said he was puzzled by the move and had been watching the reaction on internet newsgroup discussion forums.
"One poster was debating whether to upgrade his Powerbook or to go on holiday - there was no point in him buying a Powerbook if it was going to be obsolete in 18 months' time," he told the BBC News website.
"Apple has sent a strong signal that it would be sensible to wait a year if you want to buy a new Powerbook."
Apple said the change gets around issues it has previously had with chip supplies, as well as the power versus heat problems it has with IBM chips.
But, added Mr Barnett, the move was confusing because IBM's PowerPC was about to be produced in huge volumes because of its deal to provide the microprocessors for the next-generation of Microsoft, Nintendo and Sony games consoles.
Its OpenPower initiative, aimed at device manufacturers, was gaining headway too.
It is aimed at improving the market presence of the Power architecture through open standards development.
Mr Barnett said he would have been more impressed if Apple had decided to switch to AMD processors instead. AMD had "out-innovated" Intel in terms of its 64 processor technology, he said.
"Everything around PowerPC seems to interesting and optimistic - AMD can be classified as that too. Intel is just the current leader, albeit it by a big margin."
But there was no doubt that the move would have a significant impact on software vendors. A lot depends on getting the Mac developers on side at an early stage.
The company announced on Monday the release of the Developer Transition Kit with an Intel-based Mac development system and preview versions of Apple's software.
It will let developers prepare versions of their applications which will run on both PowerPC and Intel-based Macs.
MacFormat magazine's Mr Barlow said reaction from Mac users had been mixed, from "Hell has frozen over" to "Apple's transition has come full circle".
PowerPC will be in all the main next-generations games consoles
"Of course, people's fears are that their Macs will become obsolete when the new range of Intel-based Macs come out in 2006," he said.
"But ultimately it means faster Macs and more choice for the consumer, which is a good thing."
Others think the move shows that processor brand is becoming increasingly irrelevant.
Mr Barlow added that it would open a plethora of opportunities for Apple in the computing market.
"Apple may have lost the war for the office environment to Windows, but it wants to win the next war - the battle for control of your digital entertainment," he said.
"With the iPod and iTunes Music Store it already owns most of the digital audio market, but it's going to need new devices and new technology to get control of the emerging downloadable movie market too.
"These are the kind of possibilities that the Intel chips provide with their low power consumption and built-in digital rights management."
It could also pave the way for the quicker adoption of Wimax - ultra fast wireless net connectivity which Intel is touting and other developments in wireless portable devices.
Apple previewed a version of Mac OS X Tiger, running on an Intel-based Mac, to more than 3,800 developers on Monday.
According to Mark Sparrow, technical editor for MacFormat, software will be available for both processors through Apple's Xcode development platform that can compile code for both processors.
"Install CDs will contain something called a unified binary which will install the appropriate version depending on the type of processor in the Mac.
"Older PowerPC software will run on the new machines thanks to a special ultra-light emulator called Rosetta," he said.