Wouldn't this thread be the Encyclopedia for Dead Rising 2? There's plenty of other games that have them, and they work great. This one isn't any different. Having all of this information in one place is a lot easier than browsing the forum looking for a walkthrough/guide for a specific achievement.
Now, I know that once an achievement guide/roadmap is stickied, it is no longer needed in this thread, but having everything else is great. Perhaps the title can be changed to Dead Rising 2 Encyclopedia? Since that's what it is?