Hey, I'm always up to ramble about my home system, ask half the boards. But I suppose I don't talk about my setting much, just the rules, lemme see how much I can blab (I'm pretty sure at least one of my players reads these boards so... spoiler free, unfortunately).
I'm running games in a homebrew world that began life as a relatively by-the-books high-fantasy renaissance era world that I've let my players, over numerous campaigns, change to their whim with their characters plot-driven actions. Since then (we started using this world in early 2010), the world has become far more modern- for whatever reason my players have largely focused on advancing and actually bettering the world.
Now, there is common alchemy and weak magic, with more powerful and dangerous magic growing less and less common, and the tech level has reached a sort of "early steampunk" by having a great deal of early industrial-era technology suddenly injected into it, as well as a series of major advances in commercial magic usage.
Oddly enough, through their actions, peace, alliances, and trade agreements have been formed between kingdoms separated by hundreds of miles of dangerous outlands, while the five centerpiece kingdoms are all on the verge of war (and one on the verge of war with itself).
Right now my players are hires for a new sort of job- express delivery- for the Guild of Tradecraft, a guild some of their former characters helped found in an earlier campaign along with the creator of the first Airship (which they then touted to every Monarch they could, giving their inventor friend a -lot- of business).
There are two stories unfolding, one of the players as they take delivery assignments and learn more about the friendly but strange count whom they assisted in the introductory game and have since also begun working for, and the other through cutscenes where they see the tale of an intelligent paragon of an orc who seems to be leading devout followers to some dire event with a long-since thought out plan. All the while they're seeing where their two jobs intermingle with one another and with their past character's actions, and how the two seem to be leading them on the tail of, and eventually into conflict with the orc.