Why use Xowiki? Xowiki is nice, and is probably a better tool for documentation, as opposed to help. Help should hopefully be short and simple.
I want to definitely implement something into core OpenACS. I think its very important to give users context appropriate information and it should be part of core. That's why Xowiki really isn't the right answer. Maybe there is a way to combine short help, with xowiki for a full documentation type solution.