QEMU webOS Emulation
Extracting a valid initrd and kernel from the nova-installer-image-castle.uImage as supplied with the webOS Doctor .jar (for 1.0.2 - not figured out for 1.0.3 webOS Doctor).
dd if=nova-installer-image-castle.uImage of=installer-ramdisk.gz skip=2217988 bs=1 dd if=nova-installer-image-castle.uImage of=installer-kernel.gz bs=1 skip=12956 count=2204861
These commands take a very long time to run because bs=1, so be patient.
Building on OS X
Download qemu source and configure it:
./configure --disable-sdl --enable-cocoa make
Thus far there has been no success getting qemu to boot any of the images inside of the webOS Doctor jar file. It is believed this route may be somewhat of a dead end without pulling code from the phone.