I personally think it's good to 'refresh' some tips and tricks using tools such as conlog, RconJ etc, but I'd imagine most people signing up for this newsletter would rather see these tips as that, and not articles in themselves.
I've only been receiving these newsletters for a couple of months so I may be already looking at things you've mentioned, but here are some ideas that may be others would like to read about:
NAMP. It's new and quite a lot of stuff will run on it with very few modifications. For something fun I'm running NetJuke MP3 jukebox on my NW6 server, and apart from not automatically updating the music lists when I add new files, it streams just fine, with a nice web browser interface.
I've also heard of a helpdesk system written with Apache/PHP/MySQL in mind that aparently runs on NW, and an online web photo gallery app. SourceForge is a great place for this type of stuff, and a few people have even started www.osnamp.com. I think a couple of articles on useful (and playful) products running in the NAMP environment and how to set them up would be a lot of fun for us to read, and try.
There are also a lot of free tools that can make people's life a little easier. Just one to mention is Webalizer which is ported to NetWare and I use this to produce HTML reports from my web server logs with nice graphics of who's visiting my site, what the most popular pages are, where they're coming from etc...
Also what about NW6.5? It's in public Beta now and I'm sure a lot of us would like to hear what's in it and what makes it better than NW6?
Just some ideas.
SteveC