All TAC blogs, articles, and Repository items (with isolated exceptions) are enabled for comments. Old comments from the previous site will reappear before too long — it just takes a while to import them into the new system. One of the tweaks we’ve begun to implement to the new system is to make the comment counters more obvious. This morning the count only appeared at the end of an individual post’s page. Now they appear at the end of each post (or post excerpt) on each of the blogs. We’re looking into getting them to appear in the feeds on the homepage as well.
Comboxes are at the bottom of an entry’s or article’s page, beneath the Kindle edition ad.