Today's Heroes of Shadow excerpt pertains to shadow magic, and all that that entails. I like that it specifically addresses what exactly differentiates it from arcane magic (or really, any other power source). Where arcane magic often requires rigorous study (warlocks are lazy), shadow magic involves using various rituals to exchange part of your soul, or simply embracing the dark side.
Wait, shadow scholarship? Scratch what was said before, as it looks like some still have to study in order to use shadow magic. Also, it involves negative emotions and the "darker aspects of arcane/divine" power. So, more or less the grim-dark of arcana. Since this is how it operated in past editions, I'm not too disappointed, just confused by an almost immediate contradiction.
As an added bonus, the table of contents is also available for download. It's not much, but does give us some more insight into, well, the contents.
Chapter 1 looks to be entirely flavor content, featuring information on shadow magic and the Shadowfell. Since I'm planning a campaign based around Orcus, undead, and the Shadowfell, any information is handy to have.
Chapter 2 will have the executioner, blackguard (paladin), vampire, binder (warlock), and extra options for the cleric (including the death domain for warpriests), warlock (including the gloom pact for hexblades), and of course necromancy and nethermancy schools for mages. The vampire paragon path is called the vampire noble, and since the two bloodlines (beguiler and stalker) are mentioned at the end, I'm guessing the vampire is going to be "Essentials" style. This is fine, as I'd rather have a vampire class with a narrow focus that works, as opposed to a broad implementation that doesn't.
Chapter 3 is has several pages of content each for the revenant, shadw, vryloka, dwarf, eladrin, elf, halfling, and human. Dusk elves is listed, which makes me wonder if its going to be a subrace (like the winterkin eladrin or that other elf article).
Chapter 4 features ten paragon paths (including the shadow dancer), four epic destinies, feats (with only an Adventurer category mentioned), and equipment.