Originally the Kate Daniels series was going to be seven books long, however earlier this year the authors found that they would need the Andrea/Raphael spinoff novel to occur before the next book (Kate 6) for it to work, as detailed in this announcement over here. This was the original release schedule:
1) Andrea book—5/31/2012
2) Kate 6—2/2013
3) Jim/Dali book or Kate 7—Late 2013/2014
However due to a recent family emergency, the authors have revealed that the Andrea book will now be released somewhere in August 2012 and that way the next Kate Daniels book will also be release later than the planned release in February 2013. Their publishers have been very flexible with them and also helped them in this regard, so kudos to them.
Bastard and me would like to send our most sincere good wishes to both Ilona & Gordon and also their family members in this time of personal emergency, hoping that the emergency passes and they become well again. Hoping for the best, and we exhort people show patience and give their support to the Andrews in their time of need.