Mariner, some things will load, some won't.  Some content that was installed with Poser 7 won't open--but these were seem to be Content Paradise items that I never use anyway--so in time I may simply delete them.

The .rsr to .png conversion went without a hitch; except it came up with a few items it said it couldn't convert (4 I think) and I can always resave items to the runtime and they will generate new thumbs.

I agree withTrekkie Girl though, Poser should have offered to do the conversion for me.  Like in the old days when the went they changed the bump map file format from Poser 4 to Pro Pack--the program detected the old files and automatically converted them.  The only people who would find this undesireable are those still running Poser 4 or Poser Artist.