There are other books on there that are replacements or straight up reprints of other books. S1-4: Dungeons of Dread reprints the S series of adventures for example. For collectors and nostalgia hounds, having all those options available is a good thing.
After months of nothing new, we suddenly have new PDFs...
Psionics Handbook (3.0) (Though it is listed as Expanded Psionics, the cover is that of the original 3rd Edition version of the Psionics Handbook; I have not purchased it, yet, to verify which one it is.)
Greyhawk: The Adventure Begins...
Play-by-Post is a difficult beast. I have failed more times than I succeeded with it. The trick, I have found, is to have a short scenario in mind rather than trying to think of it as a full adventure or campaign. And being as clear as possible about character creation guidelines and limits.
I also read those books as a kid. I remember being disappointed that the series didn't follow up on the "Dungeon Master" professor in the real world who sent them to the fantasy world to begin with. Seemed like he ought to have been a recurring villain or at least pop up again in some fashion...
I ran an Amazon affiliate used game store, Crazy Monkey's Asylum (online only) for a number of years that was just me selling off my collection. Of all the things I sold, I really only regret selling the premium reprints of the various D&D editions that came out during the gap between D&D 4E...
12 years old in 1988. My older step-brother loaned me his Mentzer Basic Set and I got one of my own shortly there-after. AD&D 2nd Edition came out the next year and I acquired a Player's Handbook, along with a friend's 1st Edition Monster Manual and Monster Manual II. So, what I ended up with...
It has indeed slowed to a trickle. The last classic D&D product to be made available for POD was Masters of Eternal Night back in February. A Darkness Gathering should have logically been the next item to get the POD treatment, but that hasn't happened, yet.