Some more quick thoughts as conversations I had at and after CAA UK settle into my brain. This doesn't really apply to anyone I talked to there, but as a general rule I think it's worth saying:
Don't chase the zeitgeist. It's not a popularity contest and it's not a race to see who can cram the most buzzwords into their site.
Finally, what's hopefully a quite useful link for those considering official institutional blogs: Sample guidelines for institutional blog authors.