well yes, commonly held/debated theories warrant inclusion, so that people know where to go look for more information on the topics. but personal speculation should be discussed on the forums, then if it gets espoused enough, it should be mirrored on the wiki..
edit: on the other hand, speculation such as Darmiil's is probably too much spoilers, since people might not have read the prerelease materials, and some (such as I) dont want to, nor want to know any of the story before it's released for real