Official Google Blogs Now Accepting Comments

While I've always found the official Google blogs to be good sources of information they lacked interaction as comments were disabled.

They've now changed their policy and are accepting relevant comments

From what I've been able to work out they haven't enabled comments on all their blogs as yet and Google staff don't seem to be engaging with the public. So it seems like it's a bit of a one way street. (If someone can find me evidence to the contrary I would appreciate it)

Of course not all blogs accept comments and for some people there is a very good reason why they don't. Seth Godin, for example, provides a clear explanation on his policy and it makes sense. But if you do allow comments, shouldn't you at least reply to them?