I love converting topics over to wiki and find most users have no idea how this process works. I think it could be a nice option to allow top posts to be converted to wiki simply by appending a tag during creation.
Example: A new topic with the #wiki-posts tag will be automatically converted into a wiki topic.
My suggestion is to automatically convert to wiki post by applying a tag.
Apply Tag, No menu digging, no trust levels.
Could make a nice optional feature.