This came out a couple of months ago and I've finally had a chance to look it over a bit. Here is the WotC blurb about it.
"Expedition to the Demonweb Pits is a D&D super-adventure for characters of levels 9–12. It is usable as a mini-campaign on its own, as a story arc in a Dungeon Master’s regular campaign, or as a series of small side adventures with a big payoff. The structure is very flexible and eminently customizable. The adventure uses a new combat encounter format designed to make the DM’s job easier and to speed up play.
Heroes who become entangled in the adventure’s plot soon find themselves squaring off against the agents of Lolth and Graz’zt across several planes, including the Abyss."
I'm sure most of you old time gamers (of which I'm certainly one) remember the series of 7 modules that started in G1 Against the Hill Giants and progressed all the way the to an encounter with the Lolth the Spider Queen. This isn't an updated version of that but is a MUCH better done mini campaign. It is a very nice hardback book that has a good plot and plenty of info on various demons as well as their respective goals.
My biggest problem with this is that it's designed for 9-12level characters. There is no way, IMHO, that characters of that level should survive as the description says "squaring off against the agents of Lolth and Graz’zt across several planes, including the Abyss". It certainly brings back memories of going through those modules many, many years ago. As always I welcome your comments, feedback or reviews on this book.