Last year DeWALT released the DWE357 which was AC powered.  Today they announced the DCS387 which also comes in a kit with a 5.0 AH battery.  The saw weighs 5 lbs and is only 14.5″ long to fit in between studs.  Best of all it has the DeWALT 4 blade clamping system that most DeWALT saws have,  This allows you versatility to get into to most any position.  It will be available in October for $129 bare DCS387B and $258 with a 5.0 Ah  battery DCS387P1.

DEWALT Cordless Recip Saw DCS387P1_A6