Traps & Treachery II has been out for several months, actually.
Imperial Supply will be out in late September.
Monster's Handbook I'm pretty excited about. I got some very positive feedback on the concept at Gencon, so I'm looking forward to getting it out. It is essentially a monster toolkit, containing new feats, special abilities, templates, prestige classes, and more goodies for d20 system monsters. Rather than being a "monster manual," the book gives all sorts of options for adding to, enhancing, and diversifying existing creatures.
As Mike Mearls, the author, says "this book contains one million monsters!"
Further on down the line we have a book that will really get your 3e game back to the dungeon, Greg's hard at work on Midnight, the
new campaign setting we've just announced, and a couple of other projects for Dragonstar and Blue Planet.
Don't forget our new addition, Kevin Wilson.

He's busy lining up the first couple of books in our new smaller, more focused line of Legends & Lairs books. The first book, Draconic Lore, should be hitting the shelves in about 6 weeks or so!