Sigma's DP1s is an update to the successful DP1, which squeezed almost-DSLR-esque image quality into a small body.
Like its predecessor, the DP1s has a Foveon X3 direct-image-sensor, which allows you to
"reproduce high-definition images rich in gradation and impressive
three-dimensional detail. The sensor is 20.7mm x 13.8mm, which is
around 12x larger than the sensors typically found in compact consumer
cameras.
Added features not found in the DP1 include support for simultaneous JPEG and RAW image capture, and the QS (Quick Set) function previously found on the DP2. Sigma claims that photos taken of backlit subjects will look better too, but it hasn't explained how that is achieved.
Pricing hasn't been announced, but Engadget claims that November is a likely release window.