I've been reading about new hard drive technology coming, looks like western digital are releasing 6tb helium filled drives very soon with greater capacity to come. One 6tb drive will hold over 11 hours of raw 4k probably at a cost similar to one DVCAM 180 minute tape. I think in a few years storage will be so cheap that for professionals shooting raw will make sense and compression will be entirely a delivery concern. I remember when we moved from DVCAM to AVC INTRA 100 mb I thought the data size would punish me and now it's no big deal at all, I really think we are headed for a time fairly soon when the same thing will apply to raw.