it is superseeded by pst-pdf and hence moved into the obsolete part
CTAN:/obsolete/macros/latex/contrib/ps4pdf/
Right, and because it is /obsolete on CTAN, I dropped it from TL.
Frank, I agree with your concerns.
Herbert, would it make sense to write a ps4pdf.sty that calls the
pst-pdf stuff, so old documents can continue to run?
karl