Issue #307 will have an overview of the setting, a close look at some of the most important characters, a close look at King's Landing and the ice wall in the north, a few Westeros monsters, and an interview with George R.R. Martin. We'll also include some advice on playing in a low-magic setting, so that DMs have some help giving their players the feel of the setting. For players, we'll include tips on how to mine the setting for character ideas, naming conventions, and other character elements.
I think everyone realizes that we're talking about 30-40 pages of magazine content, not the 300+ page sourcebook that could easily be done on the setting. Because of that, Westeros purists are almost certainly going to want more material. However, I think we're striking the right balance between introducing the setting to those who haven't read the books, presenting playable Westeros material for fans of the series, and keeping a nice mix of non-Westeros content in the issue.
The authors are Wolfgang and Shelly Baur. Wolf is a long-time industry veteran, having worked for TSR, Wizards, and other companies as both a freelancer and a full-time staff member.