Update: I have 20,300 articles in 2,300 threads from January 2007 up until yesterday (none have been posted today yet). I have no idea what the retention rate is going to be like, since that's already using 80 MB.

In regards to adding newsgroups, I'd like to add the comp.sys.mac.*, except that they're mostly talking about OS X and the like these days, and that's not really interesting to me. I'll see about getting the rest of the comp.sys.apple2.* news groups later today or this weekend.