Apple's announcement to move their Macs from PowerPC to Intel processors in 2005 was a huge surprise at the time. Serious reports about the plan hit the web only two days before the official announcement at WWDC 2005. The immediate reaction on MacRumors included a 2936 comment thread with some very strong reactions to the switch-up.
According to Kim Scheinberg, she and her husband John Kullmann had decided to move back to the east coast in 2000. In order to make the move, Kullmann had to work on a more independent project at Apple. Ultimately, he started work on an Intel version of Mac OS X. Eighteen months later, in December 2001, his boss asks him to show him what he's been working on:
At this point, JK has three PCs in his office at Apple, and another three in the office at home, all sold to him by a friend who sells custom built PCs (can't order them through the usual Apple channels because no one in the company knows what he's working on). All are running the Mac OS.
In JK's office, Joe watches in amazement as JK boots up an Intel PC and up on the screen comes the familiar 'Welcome to Macintosh'.
Joe pauses, silent for a moment, then says, "I'll be right back."
He comes back a few minutes later with Bertrand Serlet.
Max (our 1-year-old) and I were in the office when this happened because I was picking JK up from work. Bertrand walks in, watches the PC boot up, and says to JK, "How long would it take you to get this running on a (Sony) Vaio?" JK replies, "Not long" and Bertrand says, "Two weeks? Three?"
JK said more like two *hours*. Three hours, tops.
Bertrand tells JK to go to Fry's (the famous West Coast computer chain) and buy the top of the line, most expensive Vaio they have. So off JK, Max and I go to Frys. We return to Apple less than an hour later. By 7:30 that evening, the Vaio is running the Mac OS. [My husband disputes my memory of this and says that Matt Watson bought the Vaio. Maybe Matt will chime in.]
The next morning, Steve Jobs is on a plane to Japan to meet with the President of Sony.
More engineers were assigned in 2002, and she says that's about when rumors of the project started to appear.
Indeed, in August 2002, we reported on the first news report about Marklar from eWeek:
According to sources, the Cupertino, Calif., Mac maker has been working steadily on maintaining current, PC-compatible builds of its Unix-based OS.
At the time, it was described as a "fall-back plan", in case the PowerPC should fail to deliver. Later, reports would also claim that PC manufacturers were wooing Steve Jobs to allow them to license Mac OS X and sell PCs running Apple's operating system.
Ultimately, Apple decided to transition from the PowerPC to Intel processor in 2005. The transition was a success, and all Macs now run on Intel processors.