I just yummed for the latest updates, and made the necessary modifications to yaboot.conf to boot my new kernel. I'm still not having sound though. I've still got the modprobe.conf changes that people mentioned in previous posts.
I'm running on a PowerBook G3 (Believe its a Pismo).
I have noticed that if I log in as root, and do the sound-card detect app, it sits for a while (a least a minute), and eventually plays the sound. After that, sound works fine as long as I'm logged in as root. It does not work at all when logged in as my normal user account (sound-card detect or Noatun). As a matter of fact, running sound-card detect as a user has the effect of turning sound off for root, until I re-detect as root. System beeps work as long as I don't re-detect as a user.
Sound Card Detect app:
Module: snd_powermac
Subsequent runs of the detect app work fine (no delay).