When my group playtested D&D 4th Edition, I immediately thought that that the new rules could work well in Eberron, particular in its pulpish, high-adventure incarnation. The lost continent, the dinosaur-riding halflings, the magical technology -- it all seemed like it would mesh well with 4E's default power setting, but unfortunately, Wizards decided to destroy, err, remake the Forgotten Realms instead.
This year though, they've returned to Eberron. Like the Forgotten Realms, the Eberron is getting a two-book treatment with the release of a campaign setting book and a player's guide. The Player's Guide is out first, and a number of sites have gotten advanced review copies of the tome. Dungeon's Master has a two part review (part 1|part 2) that offers a chapter-by-chapter breakdown, hitting new classes, new paragon paths, and the mystery of the dragonmarks. They also offer some final thoughts comparing this guide to its 3E predecessors, and points out that unlike the Forgotten Realms player's guide, there's not a lot of world information in this one.
Geek's Dream Girl also dives into the new book, answering readers' questions about the book including racial bonuses and special abilities, new core races, insights into the artificer, paragon paths, and planar mechanics.
If you're not satisfied with the cultural options available to your characters in D&D 4th Edition, check out GameCryer.com's review of One Bad Egg's Hardboiled Cultures. The book's all about tearing down the cultural foundations of the various 4E races, and providing you with insights and mechanics on how to rebuild them to fit your vision for the race.
The Cortex RPG ruleset (Serenity, Battlestar Galactica) remains one of my favorite rulesets, and my only regret about Origins is that I likely won't get to play it here. There are two new Cortex-related reviews available online. The first is Dice and Men's review of the Serenity RPG
Tim Brannan reviews the PDF release of the Supernatural RPG on his blog, The Other Side. He describes the Cortex variant found in Supernatural as "Unisystem and Savage Worlds got freaky one night and nine months later Cortex was born. Now keep in mind this is a good thing for me." It's a pretty apt description, and I can see how it these rules would work well with the hunter/investigator-style subject manner.
Speaking of investigations, The Inquisitor's Handbook for Warhammer 40k is out. cbpye.net reviews the book, which introduces a bunch of new player options to the game. The reviewer takes issue with some of the new character backgrounds it spawns as being too powerful. The reviewer argues what makes Warhammer 40k unique is that it pits low-powered people against unspeakable horrors; the challenge lies in some how surviving (or at least, going down with a fight). The new backgrounds, such as "Dusk" (which allows a PC to become acclimated to the horrors of Chaos) or Gunmetal City (which gives players impressive chances to hit with guns) negate this.