Hi Jerry,
I'm not familiar with the current Apple hardware, but I suspect that the Apple cpu would be RISC (e.g. Reduced Instruction Set Cycle) based. Sun has long used RISC based cpus in their workstations. I think most Linux/Unix OS including Apple OS X are optimized to run on a RISC cpu. I think the intel cpu has the full instuction set which make it better at things like floating point math, but this adds additioal overhead/cycles to the intel cpu, while yielding nothing in functionality for must users who would never need the added insturctions.
Also apple may have a better than avareage graphics card to accelerate/improve thier GUI, which java would use extensively, because java is a very graphics oriented language.
My first though, when I visited their site, was their claim to a better java relates to optimizing their hardware to run on thier OS X unix/java OS.
My wife has a 1.8 mz RISC athon ADM CPU in here system and I have a 1.6 mz intel p4 in mine. When bringing up the home page on my web site, a java window in which a message is scrolled across the screen really fly on her machine, while on mine it just slowly labor across. I kind of wish I had optioned for the ADM cpu instead of the intel.