History of Mac Pro Rumors
From Mac Guides
On June 6, 2005, Apple announced that they would be transitioning the Macintosh to Intel Processors. The news came as a surprise to many. At Macworld San Francisco 2006, it was announced that Apple would complete the transition by the end of the year. Apple was not explicit about the sequence of the transition, but it was speculated that the PowerMac would be one of the later models to undergo a change of processor. This speculation became fact, as the Mac Pro became the last model to be transitioned, at WWDC 2006.
Earlier rumors about an Intel based PowerMac were sparse and usually lacked much detail:
- It had originally been speculated that such a computer would use Intel's upcoming Conroe chip.  Early speculation also suggested that Intel's Woodcrest server chip could be used, which is now seen as the far more likely chip as it's cheaper at the high end and can be used in SMP configurations to allow the continuation of a dual dual-core configuration.
- The motherboard design for the new PowerMacs may have been contracted out to Intel. 
- While the PowerMac may keep its name, a change is highly possible, following the renaming of the PowerBook and iBook. Of note, Apple trademarked the name Mac Pro in New Zealand in late 2005, and then in the US in May 2006. 
- According to research by UBS Investment Research, new PowerMacs could be announced by September 2006.  Citigroup analysts have chimed in to add that they believe new models could arrive as soon as August 2006. 
In the weeks preceding WWDC 2006, a number of rumors appeared giving much more specific information than previously:
Early July 2006
- ThinkSecret reported that an Intel based PowerMac would sport a "substantially different" enclosure and come in both single dual-core and dual dual-core configurations. .
- Most rumor sites agreed that an Intel based PowerMac would be announced at WWDC, as well as several analysts such as Shaw Wu. 
- AppleInsider claimed that Intel based PowerMacs would use the Woodcrest processor, while ThinkSecret maintained that the Conroe processor would be used. 
- Some analysts speculated that include Blu-ray drives in future Mac Pros, although probably not in the first models. 
- A report from AppleInsider claimed that Intel based PowerMacs would gain dual Optical Drive slots but come in a similar enclosure to the current PowerMacs. Another source independently confirmed the Optical Drive rumor, and sent possibly specifications to both AppleInsider and MacRumors.