I was just thinking as I updated my guide today: If Jame did implement an update notification system, I wouldn't want my readers to be bothered by every little typo fix/etc. The system would need to include a "minor edit" button similar to the one many wikis use. This would allow the author to only notify the readers of more important edits, such as additions to the guide or major changes to existing sections. The "Log Message" could be where the author notes the changes made, and which tells the reader what chagnes were made.
I think this would be an extremely useful addition to the site, and is the one I am most looking forward to once Jame has finished his Northrend guides :)