If someday you want to go back to OS X and blow away your Windows installation, simply boot from the OS X disk, at the installation screen, select Disk Utility from the toolbar at the top of the screen, partition and format the disk for OS X, then exit Disk Utility and proceed with the OS X installation.
However ... I am in full agreement with the other posters in that I would maintain a dual boot system with a small OS X installation and set the default boot to Windows if that is your desire. That way, you could still boot into OS X for software and firmware updates as needed. You would only need about 15 GB for the OS X minimal partition and could use the rest of the disk for Windows.
-howard