James Governor has some good points about blogs and wikis vs. traditional content management - he's spotted a win for blogs as a back end vs. Lotus. Now, he's caveating this, and I agree with him:

I should stress again that this is an outlier rather than a full-blown trend. On the other hand, it should become increasingly clear to IBM, Microsoft and other content management, portal and collaboration players, that something is afoot. As RedMonk has argued before, blogs and wikis can in many cases functionally replace large scale content management and messaging platforms.

This is a trend that anyone looking into CMS should follow - look at your actual needs, and see whether a full blown CMS is actually what you want. It might be - or it might not