There are still a lot of tables here. Getting rid of the remaining tables, tightening up the HTML so there are fewer extraneous wrappers around elements, and using classes and IDs more deliberately would go a long way toward making a better interface possible.
UPDATE (requested by Gorgonzola): why tables are bad
The problem with tables is primarily one of inaccuracy, but this is obviously not a site striving to win any awards for its semantic markup, so that might not seem directly relevant. HA. This is a site with a wealth of content, and little else to show for itself. For the benefit of those who've put their time into creating content here, that content should be marked up correctly so that it's more findable, and perhaps even one day consumable. However, it would be a lot more findable if the site didn't look like a museum piece and could be updated with a more modern, more tightly edited UI. If you want an additional update on the importance of a good UI, let me know and I'll talk your ear off. Assuming we're already on the same page though, removing the tables and replacing them with elements that don't dictate their layout in regard to the elements around them makes it much easier to move pieces around, show and hide them based on a user's selected level of granularity, and of course to style them as containers for content instead of cells in a spreadsheet. Done correctly, this should reduce page weight, requiring both fewer HTML tags and less CSS because less nesting (and therefore less inheritance) will be needed. It'll make it easier for any JavaScript traversing the DOM for elements to act on to find what it needs. And it'll make maintainability easier because there will be less junk and more content (or its substitute, template tags). You should see an increase in both page and development speed. Also it's the correct way to write HTML, and has been for over a decade.
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Also, as far as the interface, condense FAQs and administrative functions (Epicenter, Vitals, etc.) and make them available as a drop-down menu. Reserve the right bar for status stuff like Other Users, New Writeups, and the catbox. Move current user information from the Epicenter to the top of the page so it's always available but not pushing other content down.
Remove "printable version" links and use a print stylesheet.
Allow creation of untitled scratchpads.