Some ideas what new port categories could be. This is not about two-level categories, because those are not going to happen, anyway.
education for educational application, including these ports.
games-arcade (games-arcade) for arcade games, about 63 candidates. Needs updating.
geography ports/64304 GIS, GPS, xearth, geoip kind of stuff. About 40 proposed ports, mainly from astro and graphics. It is currently a virtual category.
ide for Integrated Development Environments. This was mentioned in the recent Eclipse bikeshed (see below). Eclipse is not the only IDE in the tree. Some people feel the IDEs do not really fit well in any individual category. There would be a few dozen ports.
spanish ports/67531 from Jose Rodriguez. Not enough ports for it, suspended.
voip or net-voip, perhaps? Haven't checked how many voip ports we have yet.
eclipse: At the very least it should be a virtual category. There would be at least 25 ports.
emacs: It seems very odd that we have an elisp category but not emacs. There would be at least 100 ports.
fpc: There are at least 60 ports with the prefix 'fpc-' (FreePascal).
inputmethod: Just like the way NetBSD did that. There would be at least 20 ports.
latex or TeX ports/43771: There are at least 50 in the former.
Mavvie want to rename dns to net-dns to match net-mgmt, net-im and net-p2p. AMDmi3 suggests that it'd be nice to rename irc to net-irc as well then.
tlp want to split games into subcategories.
Split crypto out of security, xml out of textproc, perhaps?
Split www into pieces, for example, www-servers, www-browsers, www-apps, and leave rest in www. Also check Mavvie's old post.
Thomas Abthorpe wants a new category i18n. The discussion
Categories slated for removal
java: general consensus on the freebsd-java list is that java was a botch as a physical category (it is the only computer-language-specific category). Current consensus seems to be to discourage adding new ports there and instead just list it as a secondary category. If it remains as a physical category it should only have the JVM-related stuff in there; everything else should move to be like the rest of the ports tree.