Here are my picks from the New Mysteries featured on the Stop, You're Killing Me! New Hardcover list and the Fantastic Fiction Mystery page.
Most of these books are to be published in September, October and November 2012 and are available on the SILS catalogue to put requests on:

Death in the Floating City
by Tasha Alexander
[# 7 with Lady Emily, a young widow in Victorian London]
Death’s Door
by James R. Benn
[# 7 with Billy Boyle, a Boston cop from a family of Boston cops, on the staff of distant relative, General Eisenhower, during WWII]

The Snow White Christmas Cookie
by David Handler
[# 9 with Mitch Berger, a New York film critic, and Desiree “Des” Mitry, a black police detective, in Dorset, Connecticut]
A Death in the Small Hours
by Charles Finch
[# 6 with Charles Lenox, a gentleman sleuth, in 1860s London, England]

The Buzzard Table
by Margaret Maron
[# 18 with Deborah Knott, district judge in North Carolina]
Smoke Alarm
by Priscilla Masters
[# 4 with Martha Gunn, the coroner in Shrewsbury, England]
.

The Blackhouse
by Peter May
[# 1 in the Lewis trilogy with Fin Macleod, a detective inspector in Edinburgh, returns to his birthplace, the Isle of Lewis, in the Outer Hebrides of Scotland]
Paradise City
by Archer Mayor
[# 23 with Joe Gunther,
now head of the new Vermont Bureau of Investigation]
Seven Days
by Deon Meyer
[# 3 with Benny Griessel, an aging, alcoholic police inspector in Capetown, South Africa]
Looking for Yesterday
by Marcia Muller 
[# 30 with Sharon McCone, a legal investigator and private eye, in San Francisco, California]
Say You’re Sorry
by Michael Robotham
[# 7 with Vincent Ruiz, a detective inspector, and usually Joseph O’Loughlin, psychologist, in London, England]

The Other Woman
by Hank Phillippi Ryan
[# 1 with Jane Ryland, a disgraced newspaper reporter, and Jake Brogan, a homicide detective, in Boston, Massachusetts]
Blood Lance
by Jeri Westerson
[# 5 with Crispin Guest, a disgraced knight reduced to living by his wits on the mean streets of 1384 London, England]
posted by Sharon

WHAT I'M READING NOW:
Watching the Dark
by Peter Robinson
British police procedural
Book # 20 with Alan Banks, Eastvale detective chief inspector, in Yorkshire, England
Description: When Detective Inspector Bill Quinn is found murdered in the tranquil grounds of the St Peter's Police Treatment Centre, and compromising photographs are discovered in his room, DCI Banks is called in to investigate.
It emerges that Quinn's murder may be linked to the disappearance of an English girl in Tallinn, Estonia, six years earlier. While DI Annie Cabbot looks into the case in Eastvale, Banks travels to Tallinn to track down leads in the dark, cobbled alleys of the city's Old Town. . . . Fantastic Fiction
First book: Gallows View