Yes, there will be two zaidi The City of Lost Souls and the City of Heavenly Fire. There will also be two zaidi in the Infernal Devices series, one is called Clockwork Prince and i think the other is Clockwork Princess. They should be fantastic. I know I'm excited!!!
On the website City of Lost Souls is 5/1/12, for City of Heavenly moto 9/1/13. Should be amazing also she is probably going to be very busy making the movie that is coming up soon.