Granted cataloging is only one topic I cover and I have changed focus since I started around 2001 (art/photo> more personal> technology>everything). Blogging has been a very positive experience for me not only in terms of my own professional growth, but in documenting my body of work, creating an avenue of discussion, and giving back to librarianship through sharing my knowledge and experience.

I don't think professionals need to blog daily (I don't) nor do they need to blog, but we do have an obligation to share through some avenue. Listservs and other forums (as you mention), published articles, and/or social media may work better for some individuals.