The majority of listings affected for me were in the toy category, with just a couple of book listings. I've gone ahead and dealt with just the "Required soon" Item specifics, and will deal with the "Add recommended" Item specifics when I have time. For my book listings, the only specific I had to add was the Book Title, all other specifics had been carried over correctly.

I've done this on the assumption that the 24 hour period specified by ella has passed, and that things have now settled down with all listings in their correct new categories.