@datdude
Ultimately, I think what you are referring to requires a major modification of YABB to provide (to use Microsoft-ish or Novell-ish) "This solves my problem" code, and also the WIKI code to auto-enter the forum solution to problem 'xyz' into the wiki. While not denying the usefulness of your suggestion, the practicality of the suggestion is an issue.
If the forum had a "This solves my problem" option, then it would be halfway there. However, given the lack of support by the forum software to do so, and the (and I may be uniformed here) lack of the support of the wiki application to accept such an entry, it would require a lot of manual filtering by JR to make the system work.
At the end of the day, unfortunately, these issues are most likely prohibitive (without significant amounts of user interaction) to the solution that you suggest, especially given the fact that a topic often doesn't reveal its true nature until about the 3rd reply by the original poster as to their precise problem, and then 20 replys to said problem of which the 3rd or the 7th may the the one that "This solves my problem".
Once again I don't deny the usefulness of your suggestion, just it's practicality (personally, I would like to see it also).
Cheers,
C.