I was also looking over on Jeaniene Frost's blog and saw this frequently asked questions that she posted:
Q: I see your next two books are spin-offs of the Night Huntress series. Is DFAEG the last of the Cat and Bones books?
A: No. There will be at least seven Cat and Bones books. Right now I'm planning to end their storyline at seven books, unless Cat and Bones need another novel to wrap things up in (they aren't cooperative all the time, you know ;).
Q: Will Cat and Bones show up in the spin-off books?
A: Yes, Cat and Bones both appear as side characters in the Night Huntress World books.
Q: What are the Night Huntress World books, anyway?
A: They're novels that showcase certain side characters from the Cat and Bones books as main characters. For example, FIRST DROP OF CRIMSON features Spade as the hero, and it comes out Feb 2010. The next novel, untitled as of now, is Mencheres's book, which comes out October 2010.
Q: Are the spin-offs the start of a new series for each character?
A: No, they are stand-alone, one-and-done novels.
Q: Will you only do two "side character" books? Because I want you to do a book on [Vlad, Tate, Ian, etc].
A: I'd love to do more spin-off books on other characters. We'll see how it goes. Cross your fingers for me!
Q: When's the next Cat and Bones book coming out?
A: One For the Money, a Cat and Bones short story in the DEATH'S EXCELLENT VACATION anthology, comes out August 2010. The short story is set after the events of DFAEG. Cat and Bones's next full-length novel will come out sometime in late 2010/early 2011 (exact date to be determined).
If you've never read Jeaniene Frost's night huntress series. Go check it out. I highly recommend it. Its a Urban Fantasy/Paranormal.