Seems to me that most online debates are sorely repetative. They also tend to get rather heated, and the quality of argument tends to decline with increased heat.
There was a wonderful website that did this for the 'Intelligent Design Debate'. It had arguments and counters on both sides, to an impressive depth. I wish I had the URL!
Here's another debate, that is nominally about the coherence of the so-called 'pro-victory' stance (to be distinguished from 'pro-war'). But really, it's hard to say what this debate is about, but it touches on the Iraq war, George W. Bush, Al-Queda, U.S. foriegn policy, and general matters of personal and civic ethics. Last but not least there are issues of logical fallacy and debating etiquette sprinkled throughout the discussion.
It would be nice to apply the ID-style format to discussions like these, so that people interested can navigate the argument tree, make corrections as they see them, and expand the tree (ideally) until someone confronted with the debate could very quickly discover where they stand and why.
Judging from the quality of online debate, it is likely that even if such a resource existed, it would probably be ignored (or forgotten, as in the case of ID!) Ordinary people do not like being confronted about their beliefs. Many times I've seen people get angry when presented with obvious proof of an inconsistency, and choose to simply ignore the inconsistency and go on believing. Tradition is a powerful force in belief and in debate, and one which cannot be ignored!
Luckily it doesn't require too high of an education to get past this first hurdle. The next big issue is keeping someone's interest. Someone with education, in our society, is probably doing quite well and has a lot of options for how to spend his or her time. Debate is not an option many people choose. Especially not debate where repitition is not encuoraged, and so requires some study before beginning.
The system I envision differs from the static model of the ID site. Let us say that the website hosts debates - call it debates.org or greatdebates.org (as we're only interested in big debates, not little ones). Every debate would have to be defined and begun with a seed, that could be expanded upon by others. Additions to the debate tree, called debate nodes, would be judged according to several criteria. Points would be subtracted for fallacions argument (ad absurdem, ad hominem, ad authortatim, etc), repeating other arguments (adding noise), etc. One might realize that an argument is repetative, but like the way it sounds - in which case one could add an isomorphic node.
Eventually (and probably sooner rather than later) I can see these debate trees starting to touch at their leaves: an argument in favor of one assertion can also be used for another, etc. Indeed, I imagine that most debates held in this matter would follow the same general pattern: an initial rush of very concrete nodes, supported by more general and more abstract nodes. The very tips of the debate tree would inevitably be foundational epistemic questions familiar to philosophers, but rarely considered by anyone else.
Most great debates at this point in history, the nodes of any given important debate tree already exist online. Therefore there is an oppurtunity to gather those resources into a coherent whole.
Last but not least, some debates are heavily influenced by history as it happens. That is, by the news. Every new news item has the potential to influence some debate, even if it is just a single entry in support of a particular point. Users should get some points for doing that sort of work.
Some caution is needed. The ID debate is singular in that it attacks science on it's own turf. Since it is not a political debate, you see a lot of scientists being involved, and a debate tree would appeal to scientists. It's also a special debate in that the question of the debate is simple: is intelligent design true? related questions like "is ID a valid scientific theory" are part of the debate, but not the central issue. It might be harder to pin-down the exact core of the Iraq war debate, or the Guantanamo debate, or the domestic spying debate. If you pin it down too strongly, you risk severe fragmentation down the line, 'severe' in that the debate looses coherence.
All debates fragment. For example, let's say we are debating whether or not it is just to indefinitely detain people from around the world without trial or access to legal counsel. The canonical left response would be "no!" the canonical right response would be "yes!" and a moderate response would be, "yes, but only under the right conditions." Those conditions might include, for example, the duration of a hypothetical war. This brings up the interesting question of how long a "War on Terror" will last, etc.
The experiment is worth doing.