Hi Ken, As Lee Jay points out, PSD is a supported file format as long as files are saved with "Maximum Compatibility" option on. There's already a topic for
Lightroom: support for un-maximized PSDs. Right or wrong, this was a conscious decision by the Lightroom team to require PSDs be saved with the "Maximum Compatibility" option. You can see the arguments for and against this in the topic and add your vote there.
We should probably make this topic a request for cataloging support for PNG files...