An article about Heroes of the Feywild just went up today on the WotC website, and I figured I'd share it here. Most of the discussion on the WotC forums has been regarding mechanical optimization, and I like that these articles take a step back and view the book from a different angle. Seeing as I've had the book for several weeks now I've already soaked in much of the information, but this article provides some interesting tidbits that I overlooked as well as the author's reactions to some of the material.
First of all, tying together the references to fey bargains and souls was a nice touch. There was a lot of backlash over why the Witch wasn't a Warlock build since the two are both arcane spellcasters who make pacts with otherworldly entities (and there is even a controller subclass of the Warlock, even if it is terrible). I was admittedly among those who thought making the Witch a Wizard build was stupid. But the thing is, difference between the two classes isn't who their patrons are or even the nature of the pact, but rather how that pact is made. It's a subtle distinction, but I think it's important. The Warlock deals directly with his patron, whether that's by physically meeting with them or through some other means. It's straightforward, even if the Warlock doesn't necessarily know all of the terms of the agreement. The Witch, on the other hand, is chosen by their patron and visited by the familiar, which is the patron's emissary.
There is an air of secrecy in everything about the Witch - the Witch's power is gained by the familiar speaking arcane secrets (as opposed to the Warlock, who just gets his power). This is why it makes sense that the Witch uses Int, since it takes a sharp intellect to interpret those secrets and employ them. The Warlock's power is determined by their Con (how much power they can handle) or Cha (how much they can persuade the patron to give them). At the end of the day, the Witch is still studying for her power, albeit from a very biased source (the patron, through the familiar). Augury is a divination feature that allows the Witch insight into some of the campaign's secrets. Finally, a Witch has to be secretive about how she practices, since (as the article emphasizes) there are witch hunters everywhere. I hadn't really thought about the covens much since I haven't looked much at the Witch in general, but I like this structure for class features (it parallels the different circles that Druids join).
I hadn't caught the "fey bargain" mechanics of the Sidhe Lord theme, and I hadn't thought much about the powers for the Tuathan that I noticed. Now that it's laid out though, it does fit the flavor of the Feywild very well. Even if those options aren't terribly strong mechanically, becoming a minor patron of sorts could be appealing to a lot of people. I especially like the story of how the author's character convinced the Warlock that the Winter King would buy his contract from Asmodeus. VERY nice touch.
Perhaps my favorite part of this article is the author's discussion of the book's art. I'd registered that the art tells a story, but I hadn't paid enough attention to note how much it conveys the characters' personalities. Of course Andronus ate the hag's cookies, because Satyr's are hedonistic! Now that you mention it, that's one of my favorite pieces as well. Seeing these specific illustrations next to each other also provided a contrast between Lyrindel's and Nistyncia's very different reactions to how his aloofness and lack of caution can cause trouble.
And then there were Pixies indeed. This discussion almost makes me want to play one of these little buggers. The depth that he goes into regarding depicting the child-like nature of pixies is impressive, and I hadn't really thought too much about what implications that would have. It does sort of highlight how disruptive a Pixie can be, both in terms of RPing and mechanics. That's not to say that I think they're broken (even if they are "bent"), but they'll certainly be a source of friction in the party.
Anyways, that's about it. Awesome book overall, and well worth picking up. It's officially joined my "elite list" of 4e books, which include DMG2, MV, MV2, and Underdark. You're in good company Heroes of the Feywild, and you're the first player book to make the cut!