You can find next month's table of contents here. There's a bunch of free Monster Manual 2 excerpts up until the 18th, when they shift gears and start pitching us Eberron Campaign Guide goodies.
For Dragon, the article on Game Transparency sounds interesting, for a title, but I'm more interested in the monk playtest which will come out on the 11th. I'm pretty meh about the Celestian Order, but then I have no idea what it will actually entail. However, there is an Ampersand article on the same day, and they are usually packed with awesome. Oh well, even if I only like those two bits from Dragon, its still a good deal more than what I cared for in the past, so its easily worth the subscription (discounting the Character Builder). Aaaand then it wraps up with a playtest for Monster Manual 3.
On the other hand, Dungeon has a Penny Arcade adventure, which intrigues me. This surprises me because in general I dont really give a crap about the adventures in Dungeon. Not necessarily for lack of quality, but for lack of infinite time to run games. I'm curious if this something they (as in Gabe & Tycho) planned, or is it the game that they went through? I'm expecting the Cave of Tits, personally. We'll also see more stuff for Skill Challenges, which is always helpful.