Having seen it, it is just as I expected (except for a few disappointing errors in maps and such): 20 levels of what lies beneath Castle Blackmoor.
Now, I had thought that "Castle Blackmoor" itself (what lies above those 20 levels) could make an interesting book/supplement, but there's really no need for it.
*Horrors* What is he saying? Isn't he a Blackmoor fan??
Yes, I am, but the castle is home to the much loved King Uther and there is *no* reason for PCs to go stomping around inside the king's house. There's plenty of other areas I'd love to see developed first (The Dungeons of Glendower, Coot's Nest, City Of The Gods, etc.). I'm sure that when DA5, The City Of Blackmoor, materializes, it will have some additional information on the castle, but how much do we really need to know about the part of the friendly king's home where there *aren't* monsters running around rampantly?
Keep in mind that this adventure (or at least the top 10 levels of it) was the origin of Dungeons & Dragons. Changing it very much would be akin to blasphemy. There is nothing closer to "first edition feel" than the very first dungeon crawl. There would have been no need to detail the insides of the king's abode in those early days. Now, there's gaming supplements for every shop/store/market/home/etc., but back in those days, there were dungeons.
With monsters.
And that was pretty much it.
And, boy, was it cool.
I think the vast majority of "old school D&D" fans will really like it, as well as the type of GM who likes long campaign-spanning dungeons like Rappan Athuk, World's Largest Dungeon, Fast Forward's DungeonWorld, etc. I would also hazard a guess that those who liked the level of detail that went into the Wilderlands box set will really like it as well. If you tend NOT to play dungeon crawls (and I have been in campaigns where they are rare, believe it or not), it might not be for your gaming group, but it may still make for interesting reading if you have some interest in early D&D history or just want to find some interesting ideas for encounters from the creator of the game itself. I definately don't regret getting it.
My $0.02, anyway.
-Scott Moore
*Sheridan