For me, this is one of the exciting areas of development for Android. The new Android 5 release has support for capturing and saving RAW (DNG) formats. This should allow for greater manipulation of the data than what a lossy JPG capture allows.
I think the real power of the Camera2 API is in the pipelined processing and ability to send the image directly to rendecscript and such.
I dont see an advantage to having RAW data just for pictures, as it takes up too much space.