Automated mail isn't a particularly useful way for your OS to inform you of events anyway. It lacks priority sorting (without significant user configuration of their MUA) and doesn't conveniently expire uninteresting reports of low significance.
Since logs on Linux/unix systems tend to be rather noisy and can't be conveniently filtered for priority without lots of redundant logging, users tend to ignore the system logs as well. That's if they even know they're there.
The Windows error log approach is considerably better in this regard, IMO, particularly with the improved UI in Vista. All it needs is a way to actively raise an alert when a *really* critical event has been logged, such as a desktop popup.