I suppose the best 'selling' point of having an x10 Wiki is that you can find all you need in one place...and just like Starshine said, you can link to topics within the forum.
Sometimes the forum just has too many similar topics; some not answered/attended to, and some completely filled with unrelated chat....having one place where things like:
- Intro to x10 (maybe, even a background)
- Ad Codes
- TOS
- Info about suspension/unsuspension
- Help for Uploading Files/Deleting Files in your Account
- Help with Setting-Up/Modifying your Account
- [Other Help Topics]
- Info about the forums
...are all in one place, will just make it easier for first time (and long-standing) members to quickly reference what they need.
Then, if any other very specific problem is encountered or clarification is needed, just post on the forums. Then the specific solution could be added to the Wiki as a link to the forum (or added to the help text).
...A Wiki is a good idea, however an amount of time and energy is needed to put it together.