Native support to me means anything you can very quickly get into Final Cut Pro.
Native support means no transcoding. It doesn't mean it accesses the original file in its original file format, it does mean that it can take the essence and rewrap it in Quicktime without altering the data. So instead of a potentially lengthy transcode, you get a quick data import and rewrap. So your 5 minute transcode becomes more like a 10 second data copy.