Thanks for that response, James. The idea you referenced appears to have been implemented already. Students can see the peer review comments without seeing the name of the peer reviewer. My problem is that, if the "anonymous" option is selected in the peer review assignment, it means that I (the instructor) am no longer able to use the feedback/markup tools in SpeedGrader.
If I want to comment on student submissions that are also being peer reviewed, I have to download the submissions individually, mark them up in MS Word or a PDF editor, and the upload them each to the individual student's submission. In a large class, I'm afraid that that's just not going to happen.
Thanks for pointing me to the survey!