I've been doing a lot of reading outside the genre lately, so I'll get back to my recommendations next month. (Books are listed alphabetically by author. Only books received are noted.)

A Day Dark As Night: Exalted, Book 1 by Carl Bowen
White Wolf (mm, 288 pages)
Publication date: May 2004, USA & Canada

The Elfstones of Shannara by Terry Brooks, read by Charles Keating
Random House Audio Roads (4 cassettes, 6 hours)
Publication date: 11 May 2004, USA & Canada

Paladin of Souls by Lois McMaster Bujold
Voyager, HarperCollins (mm, 580 pages)
Publication date: 4 May 2004, UK
SF Site Review

The Twilight Zone: Upgrade & Sensuous Cindy novelization by Pat Cadigan
Black Flame (mm, 415 pages)
Publication date (forthcoming): June 2004, USA & Canada

The Meq by Steve Cash
Tor, Pan Macmillan (mm, 548 pages)
Publication date: May 2004, UK
SF Site Review

Tsubasa, Vol. 1 by Clamp, translated & adapted by Anthony Gerard
Del Rey, Ballantine (manga trade, 218 pages)
Publication date: 4 May 2004, USA & Canada

xxxHolic, Vol. 1 by Clamp, translated & adapted by Anthony Gerard
Del Rey, Ballantine (manga trade, 202 pages)
Publication date: 4 May 2004, USA & Canada

Counterfeit Kings by Adam Connell
Phobos Books (trade, 381 pages)
Publication date: 18 May 2004, USA

Grey Knights by Ben Counter
Warhammer 40,000, Black Library (mm, 413 pages)
Publication date (forthcoming): June 2004, USA & Canada

Survival: Species Imperative, Book 1 by Julie E. Czerneda
DAW (hc, 401 pages)
Publication date: 8 May 2004, USA & Canada

The Burning Shore by Robert Earl
Warhammer, Black Library (mm, 411 pages)
Publication date (forthcoming): June 2004, USA & Canada

Table of the Lord by Ono Ekeh
PublishAmerica (trade, 216 pages)
Publication date: 2003, USA

Midnight Tides: A Tale of the Malazan Book of the Fallen, Book 5 by Steven Erikson
Bantam (trade, 698 pages)
Publication date: April 2004, UK & Canada
SF Site Review of House of Chains

Once Upon a Marigold by Jean Ferris
Harcourt (trade, 271 pages)
Publication date: May 2004, USA & Canada
   For readers 10 and up.
SF Site Review

Thorn Ogres of Hagwood by Robin Jarvis
Magic Carpet, Harcourt (trade, 244 pages)
Publication date: 2004, USA & Canada
   First published in 1999. For readers aged 10 and up.
SF Site Review

Judge Dredd: Black Atlantic by Simon Jowett & Peter J. Evans
Black Flame (mm, 252 pages)
Publication date: June 2004, USA & Canada

The Last Alchemist by Iain McCalman
Perennial, HarperCollins (trade, 272 pages)
Publication date: 2004, USA & Canada

Vassal of El by Gloria Oliver
Zumaya Publications (trade & e-book, 286 pages)
Publication date: March 2004, USA & Canada

Sweet Miss Honeywell's Revenge by Kathryn Reiss
Harcourt (hc, 435 pages)
Publication date: 2004, USA & Canada
   A ghost story for readers aged 10 and over.

The Scylla Hexagram by Paul Riva
iUniverse (trade, 179 pages)
Publication date: January 2004, USA & Canada & UK

Dark Ages: Tremere by Sarah Roark
World of Darkness, White Wolf (mm, 285 pages)
Publication date: April 2004, USA

The Twilight Zone: Memphis & The Pool Guy novelization by Jay Russell
Black Flame (mm, 415 pages)
Publication date (forthcoming): June 2004, USA & Canada

Homeland: The Legend of Drizzt, Book 1 by R.A. Salvatore
Forgotten Realms, Wizards of the Coast (hc, 329 pages)
Publication date: April 2004, USA & Canada & UK

Gothic Wine by Darren Speegle
Aardwolf Press (trade, 220 pages)
Publication date (forthcoming): July 2004, USA
   Short story collection, featuring cover endorsement quotations from Charles de Lint, Graham Joyce and Paul Di Filippo.

Heaven by Ian Stewart & Jack Cohen
Aspect, Warner Books (hc, 343 pages)
Publication date: 11 May 2004, USA & Canada

The Atrocity Archives by Charles Stross
Golden Gryphon (hc, 273 pages)
Publication date: May 2004, USA & Canada

Heir Apparent by Vivian Vande Velde
Magic Carpet, Harcourt (trade, 315 pages)
Publication date: 2004, USA & Canada
   For readers 10 and up.

Caught in the Web: Dreaming Up the World of Spider-Man 2 by Mark Cotta Vaz
Del Rey, Ballantine (illustrated trade, 159 pages)
Publication date: 1 June 2004, USA & Canada

Olympic Games by Leslie What
Tachyon Publications (trade, 240 pages)
Publication date (forthcoming): August 2004, USA

End Games: Clan Novel Saga, Vol. 4 by Stewart Wieck, Gherbod Fleming, Eric Griffin, et al.
World of Darkness, White Wolf (trade, 592 pages)
Publication date: April 2004, USA & Canada

The Weavers of Saramyr: The Braided Path, Book 1 by Chris Wooding
Gollancz (mm, 440 pages)
Publication date: April 2004, UK & Canada
SF Site Review

Mobile Suit: Gundam Seed, Vol. 1 by Hajime Yatate & Yoshiyuki Tomino, illustrated by Masatsugu Iwase, translated by Jason DeAngelis
Del Rey, Ballantine (manga trade, 200 pages)
Publication date: 4 May 2004, USA & Canada

Magazines

Cthulhu Sex, issue 17, volume II, 2004, USA & Canada
Contributors to this issue include: Shikhar Dixit, Lee Clark Zumpe, Richard D. Weber, Ann Cory, Ralph Greco Jr., Alex S. Johnson, Anthony DiVona, Stephanie Simpson-Woods.

Electric Velocipede, issue 6, Spring 2004, USA
Contributors to this issue include: Liz Williams, Neil Ayres, Edd Vick, Brendan Connell, Jodee Rubins, Stepan Chapman, Gene P. Lass, Alan DeNiro, Michael Simanoff, Jay Lake, William Shunn.

Fantasy & Science Fiction, June 2004, USA & Canada
Contributors to this issue include: Matthew Hughes, Charles Coelman Finlay, A.A. Attanasio, Joe Haldeman, Kit Reed, Arthur Porges, Ray Vukcevich.

Fantasy & Science Fiction, July 2004, USA & Canada
Contributors to this issue include: R. Garcia y Robertson, James Stoddard, Daryl Gregory, George Guthridge, John Morressy, Albert E. Cowdrey, Esther M. Friesner.

Space and Time, issue 98, Spring 2004, USA & Canada
Contributors to this issue include: Paul E. Martens, Tess Collins, M. Christian, Elina Gertsman, Douglas Empringham, Sherry Decker, William J. Gagnon, Harley Stroh, Brian Plante.