MacBook Pro vs my PowerBook and my G5

has released numbers comparing the new MacBook Pro with both the 1.67 GHz PowerBook (the one I got) and a dual-CPU 2GHz PowerMac G5 (my G5).
Well, their only test was using iTunes (which is an Intel and PowerPC native “Universal” app) to convert a 160 kbps AAC audio file to a 128 kbps AAC.

Machine Speed Factor PBook ratio
PowerBook 15x 1.0
MacBook Pro 20x 1.33
G5 25x 1.66

HardMac concludes:

“In all test, the Yonah is not as performant as the PMG5 Dual CPU, and even in some cases it is only 20% faster than a Mac mini 1.25GHz.
In some test, Altivec is really making the difference, and the Yonah has hard time to compete.”

So does this mean the MacBook will perform better with more SSE3 code?
I would be very surprised if iTunes didn’t have SSE2/3 code in there to speed things up already.