currently laptop-mode-tools is set up to work with syslog, however the current gentoo tree uses syslog-ng instead (?). an update to laptop-mode-tools to work with syslog-ng would be practical.
lm-syslog-setup is quite a nasty script really. I'm more inclined to punt it as there are other loggers such as metalog which has a vastly different setup again. Either way, this is really an UPSTREAM issue.
upstream