Our clients working in HD for Blu-ray and DVD releases typically provide ProRes 422HQ files as masters - the quality is really as good as uncompressed 10 bit quicktime, with a much more manageable size. When we need DPX, ffmpeg will do the conversion, but for a feature film that's many hours of waiting.
On the scanning side, most of our indie clients don't scan to DPX because they're not set up to handle it themselves. Instead, they have us scan to ProRes 4444.
So, consider this a vote for ProRes support, both for import and export!