Currently the package depends on virtual/libusb:0, whilst the associated usbmuxd uses virtual/libusb:1. The libimobiledevice website also only mentions libusb >= 1.0.3. However it shoud actually be >=libusb-1.0.8 (http://forums.gentoo.org/viewtopic-t-829698-start-0.html). So it's not a good look - it'd be nice to have a comment in the ebuild if libusb:0 is necessary. I can confirm that ibusb-1.0.8 only WFM.
fixed in cvs. thanks for the report...
Cool, thanks for your efforts.