Speed...
As for the comment that non-G5 owners will be happy? Well, if reports are true, and Rosetta runs apps at the equivalent of 1/2 the Intel's processor speed, I'll be happy. I'm running an 867MHz 12" PowerBook G4 as my 'main' machine now. That means that for PPC apps, I'll be a little faster, and for native Intel apps, I'll be WAY faster.
Let's see:
Processor: Two procs, each 2.1 times as fast as the single I have now: 4.2x total. (867 MHz -> 2x1.83 GHz)
Cache: Eight times the cache (256 KB -> 2 MB,) again, running at 2.1 times the current speed. (867 MHz -> 1.83 GHz)
Processor bus: Five times as fast. (133 MHz -> 667 MHz)
Memory: A little over three times the amount (640MB -> 2 GB,) running at 5 times the speed (266 MHz DDR -> dual-channel 667 MHz DDR-2)
Hard Disk: Two and a half times the capacity (40 GB -> 100 GB,) at 1.7 times the spindle speed (4200 RPM -> 7200 RPM,) with four times the cache (2 MB -> 8 MB) (total throughput should be more than double.)
Yeah, I should see a major improvement.
Oh, and the only non-native apps I ever use on my notebook are MS Office v.X, AppleWorks, iWork '05 (don't see a need to upgrade,) and the occasional downloaded free game. (Google for Spinvaders, an addictive take on Space Invaders.)