Well, yes, it's akin to a more focused blog. And that's the point. There's already a lot of useful information out there in the blogsophere, produced by bloggers, which is of much better quality than what's on Wikipedia. Knol simply lets folks who're interested put that in a more accessible place than a random blog.

The concept and model are quite different when compared to Wikipedia, but that doesn't mean it won't work. In some ways, abandoning Wikipedia standards such as NPOV and the ban on original research make for much more useful articles - to an interested reader, it's a lot more useful to read three articles presenting three different perspectives than a single one which tries (badly) to present all three. I think it might just work, not necessarily competing with Wikipedia, but providing something WP doesn't. Let's not forget that the idea of ordering search results based on how many other pages linked to them was fundamentally different from how other search engines worked back then.