On my blogs I generally like to allow comments for posts but not for pages. This is how it has worked for me in the past (I'd say what version of WP that is but WP doesn't seem to want to tell me) when I upgraded one of my test sites to WP 3.5 this changed. Now everything allows comments and I only find a setting to "allow|disallow" comments by default on all articles (posts & pages). I have set to "allow" on both sites. One displays comments invitation for pages the other does not.
My theme, on both sites, is Twenty Ten which I had to install on WP 3.5 but on WP 3.5 this behavior is the same for the other, included, themes as well.
I've noticed information in this forum which implies that it is easy to turn comments on|off for individual posts but I cannot figure out how that is done either.
I'm quite confused about how it is supposed to work and hope there is some explanation that someone might be able to provide.