Looks like that's it. There are even some early manuals and specs that show the larger range. Looks like they limited it at the last minute before release. With a 12+ stop range of the RAW image and the extra 1.4 stops, that's still a lot of dynamic range.
You also have the somewhat limited option of the in camera HDR with 5 or 6 images. Only jpg, but...
I probably will never use the on-board HDR since I have Photomatix.