An updated version of Nokia Pro Camera (soon Nokia Camera) will add RAW as a capture option in the settings. The Lumia 1020 and 1520 will have three options: 5MP (JPEG), Dual Capture (JPEG 5MP + JPEG full resolution), and Dual Capture RAW (JPEG 5MP + DNG full resolution).
Regular readers will know that I (Steve) reported on the relative image degradation that comes with reframing from an underlying JPG file, so perhaps the option to save the full resolution file (whether 16MP or 34MP) in RAW format is an answer to this.
RAW format refers to image data that hasn't been processed yet, or at least compressed into JPG form. The latter is 'lossy' and there's always some degradation of the original picture information, albeit minimal to casual inspection. Nokia is using the Digital Negative Format variant of RAW, including some optimisations (e.g. for size and speed) but still with no loss of data.
It's now clear that reframing and 'zooming later' isn't practical from RAW images on the phone (as it the case with JPEG), because of the demands of handling the larger RAW files. So 99% of Nokia Lumia owners will probably want to keep the dual capture setting as all JPEG, while the 1% can opt for RAW as well, fully intending to suck off these higher quality (and much larger) originals into a desktop imaging suite for detailed processing.