kudzu should detect any active logical volumes and add the apropriate entries to fstab.
kudzu doesn't touch /etc/fstab currently. I suppose HAL could do it, but generally fstab-sync has been more targeted at removable devices.
Well, I don't know if hal (or fstab-sync) is the aproprieate component, but Fedora detects standard partitions whe booting, then it should also detect active logical volumes, I think. If I install Suse (with reiserfs or ext3) in a another partition, when I boot Fedora, the newly discovered partitions is added to fstab, but if I install FC3T2 (using LVM2) it is not added.
This would be nice to have but it requires a lot of upstream work so I'm closing this bug as UPSTREAM. If you want to participate in this work don't hesitate mailing hal which is the place where hal and fstab-sync development is carried out. Thanks, David