I'm totally immersed in the Smart Object RAW workflow. I've been on the fence about using DNG as SO layers, but it suddenly dawned on me that, since you're building in raw layers, rather than having access to your original RAW files easily, that DNG becomes essential to ensure an archival process.
That is, if I have separate RAW files I can always, at some point, convert them to DNG. Once they're in the file as a SO, I'm hosed. (Yes, I can extract them, but I lose all my work in the TIFF.)
Is anyone out there slamming to DNG before working with a Smart Object RAW workflow? (Is anyone working in a SO workflow even? Sometimes I feel like the only one... heh)