Uniquely named log files including date string.
The current log file directory structure is great, it makes it easy to navigate to the right directory for any given log date very easily.
However because the file names are not unique across the 'month' directories it's possible (believe me) to inadvertently overwrite the files.
Fortunately this was spotted during a copy operation prior to removing the archived data ;)
I don't know whether it's worth a configuration option or just adding a yyyymmddhhmm time stamp to the log name. Doing so would allow easy backup/archive scripts without fear of overwrite.