The latest addition to the M&P15 family of AR-15 rifles is the M&P15-22. S&W have designed what they call “the ultimate .22LR platform”. From the press release:

“In designing the new M&P15-22, our engineers pulled out all of the stops to develop the ultimate .22LR platform,” said Tom Kelly, Vice President of Marketing for Smith & Wesson. “The rifle’s operating features, functionality and durability are exactly what you would expect from any of Smith & Wesson’s tactical rifles. By remaining true to the standard AR-15 design while offering all of the preferred features found on the M&P Rifle Series, the M&P15-22 is well suited for a variety of recreational shooting applications while also being an extremely viable training firearm for law enforcement and military personnel. Shooters will find the M&P15-22 to be a great firearm for multiple uses with the reduced recoil and economical .22LR caliber ammunition.”

The rifle features:

* A3 style flat top upper receiver
* A2 front post sight
* A2 rear sight
* M4 style collapsible stock
* Quad rail handguard

Specs:

Barrel length: 16″
Magazine capacity: 25 rounds
Barrel twist: 1:15
Upper Receiver: A3
Weight: 5 lbs (unloaded)
Length: 31″ (stock collapsed)

UPDATE: The MSRP is $499 (Matt from S&W PR confirms this),

S&W M&P15-22. Click to expand.

Murdoc has a photo of the rifle posted at GunPundit.