At first glance this module is of far higher quality than the first 3 that were published. It even includes a section on adapting for other worlds including Darksun, Dragonlance, Greyhawk and Eberron. From a skim through of the meat of the adventure it seems well designed and could easily keep a group busy for a long while. There are creatures with Challenge up to 20th level included as well as a printing of the free materials that wizards put out for players.
The modules real starting point assumes 3rd level characters but it does include a mini adventure in chapter 6 for running pure 1st level characters up to 3rd.
Set in the Dessarin Valley http://forgottenrealms.wikia.com/wiki/Dessarin_River this module is close enough to waterdeep, neverwinter and balders gate to offer a familiar launching point. The included map has more detail for the area than I have ever seen before in previous products. The town of Red Larch http://forgottenrealms.wikia.com/wiki/Red_Larch gets more use in this adventure than I think it has in the past.
Good old day / night Random encounter charts make a real comeback in this adventure and will definitely add a good element of tension every time the party comes to a rest.
At the adventure start it seems to be assumed that the GM will be using the faction system but it does allow for a nonfaction start as well. The adventure is quite non linear in approach with included side quests and adventure locations that dont have to be done in order though it could be dangerous taking 3rd level pc's into the 6th level site for example.
By chapter 4 the party should have advanced to level 6 and by chapter 5 10th level. The adventure seems to finish around 15th or 16th level so truly this is a full campaign in a book.
The standard monster manual will get heavy use through the running of this module and will be required for play.
Artwork is top notch I was quite impressed. Well detailed NPC's very cool magic items and fun new monsters including the reappearance of some favorites of older elemental evil products.
Overall the module reminds me of the crammed in wealth of info from old 2nd edition products and the well written approach of 4th edition.
Free player download http://dnd.wizards.com/articles/features/elementalevil_playerscompanion