There are many of you who would like to have Mountain Lion on your Haswell machine. Unfortunately, you are SOL unless you have a developers account or do something illegal.
The good news is that you do not have to do anything illegal to get ML on your CPU.
How is this possible?
You can thank your AMD hackintosh brethren. They have made an excellent kernel that you can use.
1. Make an OS X startup disk. Anyone of the methods for creating a ML boot drive will do.
2. Go here and right-click and save the file "mach_sse4_exts". Rename this file to mach_kernel. Make sure that the new mach_kernel is in your Downloads folder
3. fire-up the terminal and type this "sudo cp ~/Downloads/mach_kernel /Volumes/NameOfTheFlashDriveYouAreUsingToInstallMLOn"
4. Reboot and install OS X
5. Reboot back to the Installer disk
6. Open up Terminal and type in "cp /mach_kernel /Volumes/NameOfTheHardDriveYouInstalledOSXOn"
7. Open Disk Utility and Repair Permissions on NameOfTheHardDriveYouInstalledOSXOn
8. Reboot to your OS X installation
You can update it to 10.8.4 but you have to follow the steps to put the modified mach_kernel back on the root drive
Q and As:
Q: I am using a nVidia graphics card. Will I have to deal with the graphics issues with nVidia because I use a kernel compiled for AMD?
A: No. You dont have those restrictions.