And here's where I give my opinion:
A published campaign setting should be a "snapshot" of the world. Lots of adventure/campaign seeds, sure. But every single product to come after that should assume that the campaign is still in that "snapshot" state. A DM can advance his game in whatever direction he makes, adapting the setting to conform to what transpired at his table, not the other way around.
There are dozens of product ideas that can come out of a published setting that don't involve altering the status quo. Eberron released the ECS, Sharn: CoT, Five Nations, Explorer's Handbook, Magic of Eberron, Races of Eberron, Player's Guide to Eberron, 4 adventures and the upcoming Faiths of Eberron, Secrets of X'endrik and Dragonmarked, plus a dozen novels, and even as the setting gets more and more detailed (and there's much more to be detailed), the status quo is still respected (and I hope it remains so for quite a long time).
Because if suddenly WotC decides that House Cannith splinters in three, King Boranel dies, and Sarlonans launch a full-scale invasion of Khorvaire, all those books become invalidated, and future books become useless to players whose games still assume that none of that happened. Stuff like Greyhawk Wars and From The Ashes are, imho, a bad idea. If you want to have such a major upheaval, make it an add-on product, like a hardcover or boxed set, with means to make it happen and a summary of aftereffects, but make it an optional add-on, and keep on publishing material for the "snapshot" scenario.