As 8of5 reports on his Guide to the Trek Collective
the Simon and Schuster website has been updated with listings for three new TOS books:
March's book is Devil's Bargain, by Tony Daniel. This will be Daniel's first Star Trek novel, but he is an established sci-fi writer, with several novels and numerous short stories to his name.
In April we have Greg Cox's The Weight of Worlds. Which is presumably the same book as the his forthcoming TOS novel which he previously referred to as The Twilight Realm. Cox is of course an establish Star Trek novelist, having written books from all of the main series except for Enterprise!
Finally in May we have The Folded World, from Jeff Mariotte. He might not be a highly familiar Trek name, but he's no stranger; having penned the SCE ebook No Surrender, and the Lost Era novel Deny Thy Father, both about a decade ago. He was also the editor of a few WildStorm Star Trek comics, has written IDW's Covert Vampiric Operations (which later featured alongside Star Trek in the Infestation crossover), and has writer numerous other novels and comics, both original and tie-ins for other franchises!