According to this thread, Team 17 will make an official announcement tomorrow about their next game and a new publishing partner for this title. But, we already know what game will be, because Gamer.nl has posted an exclusive preview of Worms Mayhem, which will be published by Codemasters in Europe and will be released this spring, for PS2, Xbox and PC. Based on an improved 3D engine with smooth craters and improved camera control, Worms Mayhem will feature new weapons including an Iron Donkey which drops from the sky, a bullet-protecting shield and an airstrike where you can drop the bombs yourself.
Update: it seems that the Gamer.nl article was removed.