Over at Mac Rumors there's an interesting piece about some rumours about the up-and-coming G5. This claims that yields of the processor are good and clock speeds have already reached 1.6GHz, while it also says there will be no problem reaching 2GHz plus speeds in the future.
The same piece suggests that Intel is still having problems yielding higher than 800MHz with its Itanium design, and suggests problems with the McKinley too.
News source: The Inquirer
View: Macos Rumors