It's becoming a tradition to release news about new Star Trek books at Shore Leave, the Star Trek con in Baltimore that treats the books as an important part of the Star Trek universe. David Henderson's blog gives the tentative publishing schedule for the next year or two.
Because of the cut in the number of books, there aren't as many surprise announcements there as I expected. There'll be a few TOS books next year for the 40th anniversary of Star Trek (and rightly so, despite the kvetching by the younger whippersnappers at the TrekBBS). I think the only thing that I don't recall hearing any hints about before is the Mirror Universe project due in 2007: two trade paperbacks with three novels each (Enterprise, TOS, TNG, Voyager, DS9, New Frontier).
One surprise: the next book in Kevin Ryan's Errand of Fury trilogy is currently scheduled for release in 2007, with no word on the third volume. I wasn't a fan of the first trilogy, Errand of Vengeance, but this is not a good thing. It may, however, reinforce the point that bigger standalone novels are the way to go when you've cut back the schedule while introducing more new series.
(Now playing: Bill Nelson, "Crimsworth," Crimsworth.)