Phillipa Gregory's The Red Queen, released August 19th 2010. This is the second of three books on the Wars of the Roses. The first, The White Queen, focused on Elizabeth Woodville, and this new book will focus on Lady Margaret Beaufort, mother of the future Henry VII.
C.J. Sansom Heartstone, released September 2nd 2010. Not strictly historical fiction, but set in the Tudor period, this is the fifth book in the Shardlake series, and if the other books are anything to go by then this is going to be worth looking out for. I found out about this author through reading historical fiction and would heartily recommend him.
Those of you who like historical fiction in general may want to look at these recent releases.
Alison Weir, The Captive Queen, which focuses on Eleanor of Aquitaine.
Suzanna Dunn, The Confession of Katherine Howard.
Emily Purdy, The Tudor Wife.