Fourth Edition: Forgotten Realms Campaign Setting
Unlike the other thread, this thread is about the 4E campaign setting Forgotten Realms so I shall shamelessly steal this from the other thread and expand upon it:
Forgotten Realms Campaign Guide
Forgotten Realms Players Guide
Scepter Tower of Spellgard
This is currently the only campaign setting that has come out for Fourth Edition and IMO, it's pretty decent. It marks a significant departure from the previous editions versions of the Forgotten Realms however. It has enough detail that any DM will find it a useful resource for making a campaign and providing an overall world to set that campaign in. It does not have the depth of lore or similar that previous editions have had, which is what leads to a lot of the negativity surrounding the setting.
Here is a run down of major changes to the setting (By far not a comprehensive list), all started by "The Spellplague", which ravaged the world and did a whole bunch of damage, which causes all the below changes.
2) Mystra, the God of Magic got killed by another God called Cyric. This is rather like being killed by the three stooges. Ok, I'll refrain from putting my personal opinion into this too much, but none the less she gets killed somehow by Cyric who was manipualated into doing it by Shar. Shar is, coincidentally the new "big evil" of the realms after accomplishing this (and Cyric was imprisoned where is going more insane for his trouble).
3) The weave and shadow weave, the way that magic users accessed magic in Faerun previously, shattered and the resulting mess created the spellplague.
4) A lot of NPCs from the previous setting are dead and a large number of Gods as well. Most of the Seven Sisters are dead or missing, Elminster was crippled and Gods have been shuffled around. One thing they did was reveal many pantheons as actually being one God with many different names, so they consolidated the number of Gods down a lot.
5) Continents were shifted with a "sister world" called Abeir (The Forgotten Realms is set on the continent of Faerun, which is in the world "Toril") replacing landmasses with places in Toril. This is where races like Dragonborn and the like originate in the new realms.
6) Many other places were simply destroyed (Neverwinter and Lantans Rest come to mind immediately) and other places were relatively unharmed in many ways. A huge rift to the underdark was opened in the middle of the place though and it actually drained a large amount of the Sea of Fallen Stars.
7) Areas of active "Spellplague" called plaguelands (predictably enough) are around the place as well. These have horrible abberant monsters amongst other things in them and are plain unpleasant to live.
8) Thay was turned into a giant nation of the undead by Szass Tam, when he almost successfully cast a ritual that would have ascended him to God hood. He's obviously not too upset by failing and is clearly thinking about expanding into his neighbours territories: probably to try again.
9) Finally they advanced the timeline by 100 years.
So that's some of the big changes that occurred, but by no means a comprehensive or exhaustive list.
In my opinion, I like the new realms. I never liked the huge amount of high level good aligned NPCs everywhere and I always felt there was a lot of previous material making it difficult to change things where I wanted. 4E FR takes a similar approach to the rest of 4E, giving you lots of ideas about adventuring, setting up antagonists for campaigns and similar. The book does this at the expense of a lot of lore and detail about NPCs that the setting was once known for. This has really aggravated some old fans and others (like me) are more happy with the increased 'freedom' to change what we want about the setting.
Personally, I find that I can go to nearly anywhere in the 4E realms, read the area and potential campaign sites and spend 30 minutes easily coming up with ways to start a campaign there. So naturally that means I rather like it. On the other hand, it doesn't give you a lot of details beyond the odd name or hint at things that are happening to go on. The 4E Forgotten Realms campaign guide though is well worth it if you want adventure ideas, a workable campaign setting to mold to your liking and a good place to set adventuring in. If you loved the depth of lore, NPCs and similar of the previous realms, I'm almost certain you are NOT going to like this: keep your old books.
The players guide IMO is a useful resource even if you don't actually like the realms as a setting. Although a fair chunk of the book is dedicated to the FR, the Swordmage, races (Drow and Genasi) and feats make it a worthwhile purchase for anyone. Especially if you want to play in the realms.
The adventure is decent quality, but requires a lot of work compared to the 'core' adventure series to get fully implemented into a campaign. It also starts at level 2, which is a real pain for DMs wanting to just jump right into a 4E campaign with the adventure and some fresh level 1 PCs. I am actually running this shortly for my Hollow Sacrifice group, I'll let you know how they find it.
Here is a map of the Forgotten Realms
It's worth noting that like Eberron (to come out soon), the only "official" support beyond the supplements mentioned above will be in Dragon/Dungeon for the realms. They have not, IMO, really been very great at supporting it thus far in either magazine and it remains to be seen if they will follow through on promises to improve it.