It is possible, it's already here for the N9, but on the N900 it's kind of pointless as the 16:9 picture on the N900 is just a cropped version of the 4:3 image. In general I am trying to keep rawcam have only features you can't do later. So don't expect things like filters or effects in rawcam. The 16:9 feature is an exception and will probably land in the N900 for the sake of consistency.