Apple's been maintaining Darwin for x86 since OS X was released. The link is in this article. They've had ISOs up since the beginning. The only thing that I see as new here is the emulator. Who wants to run an OS in an emulator, though?
There was (a long time ago (2001)) an online petition to have Apple release OS X for x86. It used to live at
www.osxonintel.com, but alas, it is no more.
If you want to run it, download and install Darwin.