I'm trying not to get my hopes up too much much, but according to a source George R. R. Martin has completed all but five chapters of the fifth novel in his amazing A Song of Ice and Fire series. The source, Senior Editor of Spectra, Anne Groell, has said that she would like the manuscript finished by the December. This would mean an announcement of a release date in January, and depending on how fast the turn around is, we could see the book around March or April 2011. Hmm... right around the same time HBO will be premiereing its Game of Thrones series. Sounds like good timing to me!
George has said time and time again that he will let everyone know when the book is completed so hopefully we'll hear from him soon. Until we do we should all table our hopes and expectations.
As much as possible anyway.