I made a motherboard change without Reinstalling Windows 7. I think, Windows 8 should be even better regarding at this.
I upgraded from (defective) Gigabyte H87-D3H to ASRock Z97 Extreme6.
First, I made markers on any SATA cable which SATA connection it used. Important is, if you had AHCI on while installing Windows, then you should turn it on too in UEFI (or just don't turn it off, unless it was off before). After connecting all cables (and the CPU), I could start Windows. But it hang on login screen. I had to use an old keyboard with PS/2 connection (luckily I had one around), because the USB driver of new motherboard aren't installed. Then I could navigate and used the CD with the drivers, installed them and deinstalled some software and driver and thats it for me.
Hope this helps, in case you get similar problems.
Edit: Ah and I almost forgot. While in the installing progress before starting Windows, I did an UEFI upgrade within the BIOS menu. That failed and luckily I have a dual UEFI system, where I can recover the UEFI. Otherwise, I had to send it back. So, unless you can recover your UEFI or is needed for CPU support or other important area, I strongly discourage you to upgrade the BIOS/UEFI.