From the Bethblog:
The April issue of OXM is now making its way to subscribers in the US as we speak. The cover story features a number of new areas and also features a host of new screens from different parts of the game, including new areas, new creatures/NPCs, weapons, etc. We don’t want to give away too much info on what’s in there, except to say it has the best ending line of any Fallout 3 preview thus far, thanks to a quote from Emil.
Look for the issue to be on newsstands the week of March 10 and keep your eyes open for new content coming from those folks in the form of a podcast or something else around that date.
So they talk about new areas and new enemies, and since I won’t have the mag for a month or so, if anyone picks it do tell us more on the revelations.
Fallout 3: A Post Nuclear Blog 