I think I’m a couple days late on this, as it’s all over the boards in various forums, but I’m going to place them here for reference anyway. This comes courtesy of Herschel, the original poster on the EN forums where I lifted this from. (My comments will be in parenthesis):
January:
Underdark Sourcebook by Rob Heinsoo and Andy Collins. 160 pages, $29.95
PHB Races Handbook: Dragonborn by James Wyatt. 32 pages, $9.95 (Wouldn’t an “ecology of” Article in Dragon cover this? I hope it’s not a lot of the same material. Maybe they are answering some of the 3rd party companies that have released racial books.)
February:
Martial Power 2 (and the power cycle begins anew… I wonder how many of these they have planned…)
Reavers of Harkenwold (HS1 Module levels 1-3) (I love they are continuing with the adventure series. Will there be continuity & a more fleshed out POL setting?)
Divine Power Cards (Meh.)
Minis: PHB Heroes: Series 3 (2 Arcane & Primal, 1 Divine & Martial) (minis addict. I love minis.)
March:
Player’s HandBook 3 (Yes! Although I wonder how many of these they can keep squeezing out…)
Dungeon Tiles: Howling Halls (I love tiles, but I think an older set reprint is in order.)
April:
Hammerfast a Fully detailed dwarven town/outpost, $12 price point. (I think this is awesome. More fluff and NPC’s can’t be bad. I sense a Points of Light campaign setting is stealthily being introduced.)
The Plane Above: Secrets of the Astral Sea Sourcebook (I can see a lot of people wanting this. Manual of the Planes probably skimmed the surface)
Minis: Monster Manual: Streets of Shadow (What? Minis named after a tiles set? Okay. Counts. Lots of nasties lurk in the shadows.)
So there you go. What are you most excited for? I can tell you the dwarven outpost book seems really cool. But anyone who knows me will tell you that I’m a sucker for dwarfs.
www. Newbie DM .com 
Phaezen
July 24, 2009
Regarding Hammerfast, there is actually a surprising amount of information about the Points of Light setting distributed amongst the various 4e books and DDI.
The dm side of me is looking forward to the Underdaek And the Astral Sea books. The player in me, who loves playing dwarf fighters, is looking forward to the Martial Power 2 and PHB3.
Kal Agrim
July 24, 2009
Thats a nice list, I hadnt looked at next years releases yet.
Im excited about the PHB3, as I imagine most people are.
Im intrigued to see what sort of things they bring in with the XPower2 series of books, I don’t think we need to see more builds for the martial classes, we need more martial classes (especially a controller).
The Underdark Sourcebook may be interesting, hopefully filled with a bunch of new monsters and possibly a mini-adventure like the FRCG & ECG had.
Im unimpressed about the PHB Races Handbook, I think 32 pages is a little flimsy, maybe they would be better doing something similar to the races of… series from 3.x.
Hammerfast sounds like it may be quite good; a drag and drop outpost is always welcome. For me, creating interesting towns tends to be more difficult than creating interesting dungeons.
The Plane Above: Secrets of the Astral Sea will hopefully be a nice book, but I still need to pick up some older books before I grab that one (Open Grave and Draconomicon 1).
Sean Brady
July 24, 2009
Tiles and Mini’s are always interesting to me. The PH3 should be an interesting book if they continue to expand and not just re-hash old stuff (in a new wrapper). I really dont care at all about the Dragonborn book. The Harkenwold, Hammerfast and Underdark books all sound good. I am not much on a planes guy.
Destrin
July 24, 2009
They’ve already done an ‘Ecology of the Dragonborn’ which makes me wonder if this Races book is in fact that Dragon article, fleshed out with a few more options and then rereleased?
My Dragonborn cleric player is excited but I guess we shall see
newbiedm
July 24, 2009
I can say I am most excited about the fluff stuff. The dwarf city really interests me.
I feel there is enough crunch in the game already to last a while, and the powers book are useless to me considering we have DDI use in our campaign and those powers are put in the character builder.
The underdark book is interesting to me as well, although I wonder if the underdark will be any different from the previous books detailing it.
Lou
July 24, 2009
@newbie
A Dwarven outpost book and an Underdark book? Do I smell the defense of this dwarven outpost from the Denizens of the underdark a la the battle of Helms Deep from LOTR’s Twin Towers?!!!! ROAR!!! (trying not to go into berzerk rage in office) lol
Zee Brat
July 24, 2009
Ooooo Underdark. I loved that setting in 3.x
The PHB3 should be pretty amazing. Was a big fan of psions. I can’t wait to see how the TK psion plays.
drchrisheard
July 25, 2009
Thanks for this. My anticipatory opinions are more or less similar to yours.