During his keynote address today at Apple's Worldwide Developer Conference 2005, company CEO Steve Jobs set out a transition plan from PowerPC to Intel microprocessors for Mac computers.
The first Macs with Intel inside aimed at the end user are to ship in 2006, though developers will be able to purchase a development system immediately. The entire Mac product line is to be running Intel processors by the end of 2007.
During the keynote, Jobs demonstrated a build of OS X 10.4.1 running on a Mac system equipped with a 3.6GHz Pentium 4 processor, notes MacWorld's live coverage. The same or similar system - running a preview release of OS X 10.4.1 for Intel - is to be made available for US$999 today to Apple developers and will ship in about two weeks.
Several Mac news web sites, including MacNN and MacWorld, updated their coverage every few minutes as the keynote address unfolded, and as of this writing are the best places we've found for details of Apple's Intel move.
An Apple press release has additional information, as does an article on cnet.