Ironside is the direct sequel to Tithe so we'll see the return of Roiben and Kaye in this one (which I'm looking forward to because I really enjoyed the two characters).
[Edited to Add Blurb]
In the realm of Faerie, the time has come for Roiben’s coronation. Uneasy in the midst of the malevolent Unseelie Court, pixie Kaye is sure only of one thing--her love for Roiben. But when Kaye, drunk on faerie wine, declares herself to him, he sends her on a seemingly impossible quest. Now Kaye can’t see or speak with Roiben unless she can find the one thing she knows doesn’t exist: a faerie who can tell a lie.
Miserable and convinced she belongs nowhere, Kaye decides to tell her mother the truth—that she is a changeling left in place of the human daughter stolen long ago. Her mother’s shock and horror sends Kaye back to the world of Faerie to find her human counterpart and return her to Ironside. But once back in the faerie courts, Kaye finds herself a pawn in the games of Silarial, queen of the Seelie Court. Silarial wants Roiben’s throne, and she will use Kaye, and any means necessary, to get it. In this game of wits and weapons, can a pixie outplay a queen?
Holly Black spins a seductive tale at once achingly real and chillingly enchanted, set in a dangerous world where pleasure mingles with pain and nothing is exactly as it appears.
Ironside will be availabe May 2007. You can pre-order from Amazon.
For more information, you can visit Holly Black's website or check out her LiveJournal.