That's an interesting and potentially good idea

If this wiki snippet is displayed on the same page as the thread, it can have a bigger effect (and traffic) than if the wiki is 'manually' linked elsewhere, like the common practice now.

The downside is that this thing will lie outside of the current moderating scope & tools, and it'll most likely be used as messy battleground if the thread is a debate thread too.

Perhaps if this wiki widget/snippet/area is only opened by request (have a poll to calculate public's interest)? Then again, for something with that much interest, usually the OP gets motivated enough to maintain his/her first post on the thread to act like a moderated wiki.