I didn't know about Libworm before, but my rather narcissistic Google Alert has brought it to my attention because it includes entries from this very blog.
Libworm collects RSS feeds from 1400 blogs, and has medical librarianship as a category. You can also search it.
It looks very useful (and I am not just saying that because it includes me, although thanks to them for that!).
There is also Medworm, which does the same thing with medical topics. (There is a mention of this in the Libworm FAQs)