Nope! I've been running with my PowerBook blissfully quiet and the update process dead for the past two days. I just rebooted into single-user mode and ran fsck. No problems were found!
The process is only resurrected upon reboot; so, you should only have to kill it once for now.
Thanks for pointing me to steve's thread. I knew
I'd seen this problem somewhere else before. I'll PM him about this thread in case he hasn't seen it.