@robbiemorrison Sorry to hear this, but I’m confused. I assume you’re referring to the Disqus-powered comment functionality at the bottom of the post when you say you want to login to the blog site. I just successfully created a new login, requested a verification email, received the email, authenticated and posted a comment without any issue.
Are you unable to log into Disqus to post a comment using an existing username/ID? The Disqus functionality has not been changed with the blog redesign so this could be a bug on their side?
I’m firstname.lastname@example.org on email if you want to send me more details.