There have been several occasions recently where the same stories were posted to both the blog and the forum parts of this site, with consequent splitting of the follow-up responses. The two look somewhat the same but work rather differently.
Blogs. Comments can only be added to the end of the conversation. The front page shows blog posts by their creation date, so entries will inevitably vanish from the front page after a few days. Blogs are ideal for one-off pieces with a limited amount of response expected (the fact of the CMS Select Committee announcement of an inquiry, Daniel Bye's Milk piece, ..)
Forums. Rich topics which need to be ongoing are better in a discussion forum, where responses can be made to individual entries and replies (rather than at the end only). The front page shows the forums by the date of their last contribution, so the active ones remain on the front page. A forum would be the ideal place to discuss the responses to the CMS Select Committee inquiry into funding.