Since Safari 7.0 which was introduced yesterday with OS X Mavericks the little terminal hack
defaults write com.apple.Safari WebKitOmitPDFSupport -bool YES
doesn't work anymore (at least not for me).
Once you use the Terminal hack, the PDF is shown in binary/ascii-format in a new tab of Safari (like if you would open the file with TextEdit instead of an arbitrary PDF reader):
Any suggestions how to achieve the desired behavior anyway?