After updating to the latest rawhide yesterday my printer stopped working. Downgrading to hplip + hpijs + libsane-hpaio from F-7 updates, fixes this. I've also tried to change the DeviceURI from: hp:/usb/psc_1300_series?serial=MY38O1F0XF9F to: hal:///org/freedesktop/Hal/devices/usb_device_3f0_3b11_MY38O1F0XF9F_if1_printer_MY38O1F0XF9F As a new "dynamic" printer was added to my cups config using this as DeviceURI, but that didn't help either. My printer is a HP PSC 1350 connected through USB, with the rawhide hplip+hpijs, hp-toolbox still saw the printer fine if run as root, but printing didn't work, ps aux revealed hanging (sleeping) hpijs and ghostscript processes. I will happily do more testing, I like the idea of getting rid if the hplip daemons, but sofar that doesn't seem to work for me.
This is caused by udev not making /dev/bus/usb nodes as far as I can tell.
I can confirm that hplip-2.7.6-9.fc8 fixes this, closing.