Actually it allows user to take either 5MP, 8MP or 38MP images so the forcing to 5MP is only optional though gives much less noise to the image. I am hoping to see this live and play around with it!
Those choices are bit odd imho, 5 and 8 are relatively close each other, and then there is huge gap to 30+ megapixels. Wouldn't it make more sense to have eg. 8, 16, 30+ megapixels?