Right. Both blog and wiki should be outward-looking, using whatever is the best for their purposes. At the same time, they play different roles: the blog is for publication of new research in the relevant area, and the wiki is authoritative reference of relevant concepts. The wiki may be a useful place to link to from the blog, by virtue of being centered on the same area of investigation as the blog, but other than that it competes with the rest of the info in the world. Likewise, the blog may be a useful place to reference in the wiki articles, but it also competes with info in the rest of the world, with standard scientific publications, with Wikipedia, etc.