I've argued with Disqus many times, even asking nicely too -- and they just won't add this feature. They say that they want to build a "core" experience within Disqus, while also allowing it to adapt to your website's colors and fonts, and so on.
I've argued the point that we can still have a core Disqus experience, but we can extend integration with a website's theme by allowing CSS support. As an answer to this, they've asked the community what they want to customize. That's a good idea, except creativity doesn't happen on a dime, and often people forget what they wanted to do. I suggest Disqus adds the CSS feature and observes what people are doing with it, and then keep CSS as a feature after the fact.
Another problem with Disqus 2012 is that it doesn't feature all of the login options from the classic Disqus. Disqus cut out some of the less-popular ones because they weren't being used that much. While it might still take resources to keep supporting the less popular login methods, yanking support for it is like dropping a feature.
Gary Rumain, a fellow community member here (and for a long time I might add), complained about font sizes and the ability to adjust the reply indentation -- that is, how many nests replies can take before they all become the same width, and you rely on the @parent system they have. CSS support, as well as settings in the admin panel, can solve his issue. The classic Disqus allowed you to control how many times you can reply to a comment, to prevent comments from going so far deep that one line is one character across.
Disqus 2012 aimed to fix that problem, and does for the most part fix the problem. The responding issue though is that we want control of how far replies nest before they start staying at the last width (It's hard to describe but if you see large comment threads you'll know what I mean).
So basically, I'm wrote this article to highlight some of the issues that I and other community members have, out in the public, and to possibly get Disqus to pay attention. I'd say that Disqus is heading in the right direction by improving Disqus, but if they keep forgetting and cutting existing core features and missing obvious and simple to implement functionality, I'd say they are not. That would be a case of them not listening to the user.