When you say "transferred everything over" what did that entail exactly?
What happens when you boot OS X on the new mobo?
But yes, I don't know about easy but unlike with Windows, it is possible, I recently moved my 10.8.x install from a Core 2 Duo P45/ICH10R system to a Core i5/Z77 system without a hitch, after setting up everything for the new hardware everything works fine. It's the same drive.
I do have a partition with a clean 10.8.x installer to work from, this is a bonus in a situation like this.
You *must* clear out the kernel/kext caches (see below) and make sure there are no 3rd party or modified Apple kernel extensions left in /S/L/E that are specific to your old motherboard.
Obviously if you were using a DSDT in /Extra and other things specific to your old mobo in /Extra (like bus or memory speed settings in smbios.plist for example) you need to get rid of those as well.
Also get rid of any kernel extensions that aren't strictly necessary for OS X to run such as drivers for hardware monitoring software and the like. Basically, go back to a bare minimum of modifications so as to minimize the chance of conflicts, this will help when troubleshooting later. Once you can get the OS to boot on your new mobo, even if it's just in safe mode, that'll be your starting point for getting everything (audio, LAN, whatever) working again.
Obviously don't delete fakesmc.kext as that is the minimum requirement for OS X to boot on any Intel PC.
The caches are at /System/Library/Caches/com.apple.kext.caches/Startup - just trash everything in there. You may have to boot with UseKernelCache=no until the caches have been rebuilt, I'm not sure if that's necessary but it can't hurt.
Most Z77 boards require a BIOS patch for native power management to work. I don't know if this applies to Gigabyte boards as well, generally they tend to be more compatible.
Please post more information, there is no way to help you if you can't be more specific about what's happening and what you did.