The Power of Six by Pittacus Lore (reviewed August 25, 2011) has a sequel released August 21, 2012, titled The Rise of Nine.
The TJ and the Time Stumblers series by Bill Myers (the first book in which, New Kid Catastrophes, was reviewed September 9, 2011) has four new installments: Switched!, Oops!, Ho-Ho-NOOO!, and Yikes!!!
In Front of God and Everybody (The Confessions of April Grace) by KD McCrite (reviewed June 30, 2011) has a new sequel, released December 6, 2011, titled Cliques, Hicks, and Ugly Sticks (The Confessions of April Grace).No Place Like Holmes by Jason Lethcoe (reviewed June 30, 2011) has a new sequel, released December 6, 2011, titled The Future Door.
If you know of any we've missed, let us know!