Looks very nice! The "perlmonks archives" contain some hidden treasures that unfortunately don't get enough attention.... I do have a couple of ideas for your interface though:

• Include the number of replies (either direct replys or nodes in the entire thread) in the top level view... My custom newest nodes interface lists that information. It helps me keep ontop of hot topics, and also lets me give some extra attention to unanswered questions. Plus its trivial to implement.
• This ones a bit trickier... Sometimes interesting subthreads sprout out of relatively mundane original threads. If the title changes significantly during the course of the thread it would be nice to see that on the top level view... noting that "Fun with closures" is burried under "My CGI is broken" would be nice to see at a glance.
• The third suggestion I have would be to parse Best Nodes a few times a day, and flag threads/nodes that made the list. I'm sure the historical data is long gone, but going forward, I think it would be an excellent way to turn your data into information. --- if you could add this before I leave for the holidays, I promise to put it to good use when I get back ;-P
• Update Another thing I could see myself using after a perlmonks absence is a way to select groups of threads based on keywords. Logging in after the holidays and getting a list of the top level nodes that don't contaion 'CGI' 'Win32' or 'Tk' ^* and with "I made best nodes" tags on them would be quite keen.

^* no offense, just picked a few strings that might be towards the bottom of my to-read list when I get back.

-Blake