Actually It is in fact shipping, although not in much quantity as of yet.
We installed a few of them in March and are currently waiting for more to arrive.
basically it bests the 12S3 in all areas, but is slightly higher in price as well.
Contrast has been increased and is such that we are using Studiotek 130 screen material now (also what Marantz was using at CES) as opposed to the grey or fire hawk material.
Although the external housing looks nearly identical to the S3 (save the paint color) nearly everything inside has changed. The DMD, The Video processors and scaling chipsets, even the lens has been changed (there are now three lens options, short, standard (mid) and long throw.
I would be happy to answer any specific questions you might have if I know the answer.