Using the latest 4.6 beta on OSX 10.5.5.
Original Canon 5D RAW CR2 shows Lens info in the Info panel using "Lens: {lenstype}"
When CR2 is converted to DNG the value shows as blank in the Info panel.
Using exiftool I found the value displayed for {lenstype} seems to be the LensModel tag? The LensModel tag for the CR2 and corresponding DNG are the same, as reported by exiftool.
Mark