I have one of the Macs release this year, but not the newest line. It's a 466Mhz G4. I just upgraded from 9.1 to 9.2.1 and when I rebooted from the update, the computer rebooted fine, but my power light went out. I didn't have time to play with it (I was updating the software before work) so I don't know if it will happen again when I boot in to 9.2.1 again. The light came back on when I booted into OSX. Just wondering if anyone else has had a similar experience.