You just reminded me with your post about asking what RAID0 does for you relative to audio production. I ordered an 8890 with 2 7200 rpm drives. I plan on running Sonar XL as the main sequencer. I know this question has probably been addressed elsewhere, but since you are using it for the same application I intend to, you'd be the best to answer it.
Also, are you considering a Powerbook G4? Apparently they are quiet since they use a heatsink rather than a fan. However, they get pretty hot (not a prob if not on your lap). Also, how would they powerbook compare to the computing power of a 3.2 GHz 8890? Any ideas?
Also, regarding noise, if the 8890 turns out to be too noisy for you, is there a scheme you can come up with to isolate the noise? For example, I was thinking you could use a USB port replicator to drive your monitor and external keyboard/mouse, and then use some sound absorbing enclosure to isolate the noise and perhaps duct the warm air away from the laptop.
I would seem a shame to give up the power and portability of this laptop when a work-around might exist.
Thanks in advance!