Some QEMU attempts through Q, A CPU emulator for Macintosh.
As of January 2010, Q.app still uses qemu 0.9.x, whereas PureDarwin needs 0.10 to function properly. Hence, we recommend to use QEMU instead for now.
The latest version (Q-0.9.1d118) has been updated last year, creating a big gap between the latest official QEMU and the one used in Q front-end.
Consequently, Q is not usable for PureDarwin at this time.
We also tried to replace i386-softmmu with a newer version inside Q.app but no success since the usage is different between both parts (and also the features supported).
Please, let us know if you have a solution.
SMBIOS well-known problem is bypassed with Voodoo kernel (xnu-dev).
Then, the real boot begins, but quickly ends with a problem related to APIC similar to the one in VirtualBox page.
http://code.google.com/p/xnu-dev (Voodoo, A fork of the XNU kernel)