I was just installing the Garage Band update on my Mac mini, when lo and behold, upon checking again at completion for updates, the 10.5.8 cumulative update appeared.
I’ve yet to update my mini to 10.5.7, because of reported issues with outputting to 720p resolution, which is the resolution of the TV I have it connected to. 10.5.8 appears to fix display resolution issues, as stated in the update description itself.
It also claims to bring the usual bug fixes and security enhancements we’ve come to expect from incremental updates, in addition to solutions for AirPort connectivity and reliability issues, Bluetooth connectivity problems, and sluggish startup times. My iMac has had some AirPort hiccups from time to time, which I’ve actually just learned to live with, but hopefully 10.5.8 gets rid of even those minor annoyances.
It’s available now via Software Update, and you can read more about it at this Apple Support article.