Puzzled

Am I being very dense? I want to comment on this announcement :

http://rhizome.org/announce/view/51105#comment

so I follow the link from the mail in my inbox and I get the post ( which incidentally doesn't show up in the list of posts on Edward's profile) but there's nowhere to post a comment…
Neither does the post show up in the discussion section which seems a bit strange
It's entirely possible I'm being stupid but if I'm not it seems strange to segregate stuff like this..a lot of discussions in the past have arisen out of 'announcements' - surely everything should flow into the discussion section on the site precisely to facilitate the widest possible *discussion*?
Puzzled, Harlow, UK.
PS Edward's project couldn't be less cool & couldn't be more enchanting & addictive. Do yourself a favour and read it all, now. That's what I was going to say.