The tree-traversal script can gather the info, and additional script could work up some sort of display. It could even create a nice graph: Modern browsers support a little-used standard called SVG for creation of vector graphics, and the script could compile an SVG "script" and feed it into the standard HTML IMG tag.

I have to say, though, that I'm not sure that particular graph would have a broad appeal. But if you frame the opportunity in terms of script being able to not only read the tree but to modify it as well, analysis-based tools become quite interesting. For example, you could re-sort the TOC to show most-active threads in descending order (the current recent-thread system is binary: at the top are all threads from the last 24 hours, internally sorted in the order they were started; and the bottom half is older threads, still in their "natural" order). More esoteric (but gratifying to the ego), you could group threads by the name of the person who started them. Or, building on your analysis, show "most-robust" threads--threads with lots of participants and an even distribution of posts across their "width" and "height"--a "spatiotemporal" measure of the "branchiness" of a thread.

Thread display format itself can be altered. It would be possible to reconstruct the TOC to list responses to a root post in a simple linear way rather than the branching tree it currently uses. There are some people in the world who actually prefer the linear display to the tree display, though obviously I'm not one of them.

Interesting, isn't it?